WorldWideScience

Sample records for clad al-li alloys

  1. CASTABILITY OF Al-Li-Mg AND Al-Li-Cu-Mg ALLOYS

    OpenAIRE

    1987-01-01

    The objective of the present work is to study the casting characteristics of various Al-Li alloys, which include fluidity and strengths of the alloys and their interaction with cast molds. Materials investigated are Al-Li-Mg and Al-Li-Cu-Mg alloys with Li content of 2.5 wt%. The results show that sand molds with resin binders are good for Al-Li casting. Ceramic coatings can further reduce the metal-mold interactions. However, the permeability is also reduced by coating. The fluidity of Li-bea...

  2. Hydrogen diffusion in Al-Li alloys

    Science.gov (United States)

    Anyalebechi, P. N.

    1990-08-01

    The diffusion coefficients of hydrogen in binary Al-Li alloys containing 1,2, and 3 wt pct Li have been determined from desorption curves of samples saturated with hydrogen at 473 to 873 K. Within this temperature range, the diffusivity of hydrogen in the binary Al-Li alloys investigated has an Arrhenius-type temperature dependence and follows the equation of the general form D = DT) where D 0exp(-Q/R is the diffusion coefficient (m2/s), D 0 is the preexponential or frequency factor (m2/s), R is the gas constant (J/K mol), Q is the activation energy (J/mol), and T is absolute temperature (K). The rate of diffusion of hydrogen in aluminum decreases with increase in lithium additions. This is provisionally attributed to the stronger local binding energy between hydrogen and lithium atoms in the aluminum metal lattice.

  3. Fatigue crack growth behaviour of Al-Li alloys

    Science.gov (United States)

    Saravanakumar, R.; Ramakrishna, K. S.; Kanna, B. Avinash

    2013-06-01

    Al-Li alloys are being used in aircraft structures due to its low density and inherent mechanical properties. Fatigue Crack Growth (FCG) resistance is usually high compared to conventional Al-alloys attributed to increased modulus and crack closure. Extensive investigations concern about the FCG resistance and crack closure in Al-Li alloys. The present work reviews the FCG resistance in Al-Li alloys and the mechanisms associated with it. The alloy 8090 is taken for the consideration and sometimes compared with 2024.

  4. The physical metallurgy of mechanically-alloyed, dispersion-strengthened Al-Li-Mg and Al-Li-Cu alloys

    Science.gov (United States)

    Gilman, P. S.

    1984-01-01

    Powder processing of Al-Li-Mg and Al-Li-Cu alloys by mechanical alloying (MA) is described, with a discussion of physical and mechanical properties of early experimental alloys of these compositions. The experimental samples were mechanically alloyed in a Szegvari attritor, extruded at 343 and 427 C, and some were solution-treated at 520 and 566 C and naturally, as well as artificially, aged at 170, 190, and 210 C for times of up to 1000 hours. All alloys exhibited maximum hardness after being aged at 170 C; lower hardness corresponds to the solution treatment at 566 C than to that at 520 C. A comparison with ingot metallurgy alloys of the same composition shows the MA material to be stronger and more ductile. It is also noted that properly aged MA alloys can develop a better combination of yield strength and notched toughness at lower alloying levels.

  5. Modeling-Based Processing of Al-Li Alloys for Delamination Resistance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Al-Li alloys are of interest for use in aerospace structures due to the desirable combination of high strength and low density. However, high strength Al-Li alloys...

  6. A TECHNIQUE FOR IMPROVING THE TOUGHNESS OF Al-Li POWDER METALLURGY ALLOYS

    OpenAIRE

    1987-01-01

    A technique has been developed for increasing the toughness of Al-Li products made by powder metallurgy. The technique which involves the addition of unalloyed aluminum powder to Al-Li powder before compaction was evaluated with Al-Li-Cu-Mg-Zr alloys (Al 8090), and Al-Li-Zn-Cu-Mg-Zr and Al-Li-Mg-Si-Cr alloys . The addition of 15% aluminum to Al 8090 aged at 422K for 40 h produced an increase in impact toughness of 215% at the expense of a drop in yield strength of 11%. The Al-Li-Mg-Si-Cr allo...

  7. Al-Li Alloy 1441 for Fuselage Applications

    Science.gov (United States)

    Bird, R. K.; Dicus, D. L.; Fridlyander, J. N.; Sandler, V. S.

    2000-01-01

    A cooperative investigation was conducted to evaluate Al-Cu-Mg-Li alloy 1441 for long service life fuselage applications. Alloy 1441 is currently being used for fuselage applications on the Russian Be-103 amphibious aircraft, and is expected to be used for fuselage skin on a new Tupolev business class aircraft. Alloy 1441 is cold-rollable and has several attributes that make it attractive for fuselage skin applications. These attributes include lower density and higher specific modulus with similar strength as compared to conventional Al-Cu-Mg alloys. Cold-rolled 1441 Al-Li sheet specimens were tested at NASA Langley Research Center (LaRC) and at the All-Russia Institute of Aviation Materials (VIAM) in Russia to evaluate tensile properties, fracture toughness, impact resistance, fatigue life and fatigue crack growth rate. In addition, fuselage panels were fabricated by Tupolev Design Bureau (TDB) using 1441 skins and Al-Zn-Mg-Cu alloy stiffeners. The panels were subjected to cyclic pressurization fatigue tests at TDB and at LaRC to simulate fuselage pressurization/depressurization during aircraft service. This paper discusses the results from this investigation.

  8. Fracture toughness of an Al-Li-Cu-In alloy

    Science.gov (United States)

    Wagner, John A.; Gangloff, Richard P.

    1992-01-01

    The crack initiation and growth fracture toughness of select AL-Li-Cu alloy variants are characterized and elucidated. Conventionally processed plates form large DC cast ingots are investigated to eliminate the variation in microstructure associated with laboratory scale and SPF-processed material. Fracture resistance is characterized using the J-integral method to establish crack initiation and growth behavior at 25 and -185 C. It is shown that state-of-the-art 2090-T81 has superior toughness compared to 2090 + In-T6 at both test temperatures, with the low toughness of 2090 + In-T6 associated with intersubgranular fracture attributed to a high density of subboundary precipitates.

  9. Effect of Impurities and Cerium on Stress Concentration Sensitivity of Al-Li Based Alloys

    Institute of Scientific and Technical Information of China (English)

    孟亮; 田丽

    2002-01-01

    A notch sensitivity factor was derived in order to evaluate the stress concentration sensitivity of Al-Li based alloys. The factor values for the Al-Li alloy sheets containing various contents of impurities and cerium addition were evaluated by determining the mechanical properties. It is found that the impurities Fe, Si, Na and K significantly enhance the stress concentration sensitivity of the alloys 2090 and 8090, whereas cerium addition reduces the stress concentration sensitivity to a certain degree for the high strength alloys. However, an excess amount of cerium addition in the high ductility alloy 1420 can significantly increase the stress concentration sensitivity. As compared with conventional aluminum alloys, the Al-Li based alloys generally show high stress concentration sensitivity. Therefore, a special attention must be paid to this problem in the practical application of Al-Li based alloys.

  10. Thermal Exposure Effects on Properties of Al-Li Alloy Plate Products

    Science.gov (United States)

    Shah, Sandeep; Wells, Douglas; Wagner, John; Babel, Henry

    2003-01-01

    The objective of this viewgraph representation is to evaluate the effects of thermal exposure on the mechanical properties of both production mature and developmental Al-Li alloys. The researchers find for these alloys, the data clearly shows that there is no deficit in mechanical properties at lower exposure temperatures in some cases, and a signficant deficit in mechanical properties at higher exposure temperatures in all cases. Topics considered include: Al-Li alloys composition, key characteristics of Al-Li alloys and thermal exposure matrix.

  11. [Determination of hydrogen in 2,091 Al-Li alloy].

    Science.gov (United States)

    Wang, X; Yang, Y

    2000-02-01

    High volatility element Li exists in 2091 Al-Li alloy, and makes the difficulty for the determination of hydrogen. A lot of tests were done, for example, how to distinguish the body and surface hydrogen, to choice heating power, heating time and the size of sample. Then the analytical method is established and many discussions were done. The reproducibility and accuracy is satisfactory, and compared with the Russian Al-Li alloy hydrogen standard sample.

  12. Influence of alloying elements on mechanical properties of Al-Li plates

    Institute of Scientific and Technical Information of China (English)

    杨守杰; 戴圣龙; 苏彬; 颜鸣皋

    2004-01-01

    The effect of alloying elements such as Cu, Mn and Zr on the mechanical properties of the Al-Li plates was studied, and the grain structure, crystallographic texture and precipitates were also investigated. It is found that the element Zr has a two-fold effect on the anisotropy of mechanical properties; the addition of element Mn can reduce the crystalline texture and the anisotropy of Al-Li plates. However, the effect of Cu element appears less pronounced.

  13. Utilizing various test methods to study the stress corrosion behavior of Al-Li-Cu alloys

    Science.gov (United States)

    Pizzo, P. P.; Galvin, R. P.; Nelson, H. G.

    1984-01-01

    Recently, much attention has been given to aluminum-lithium alloys because of rather substantial specific-strength and specific-stiffness advantages offered over commercial 2000and 7000-series aluminum alloys. An obstacle to Al-Li alloy development has been inherent limited ductility. In order to obtain a more refined microstructure, powder metallurgy (P/M) has been employed in alloy development programs. As stress corrosion (SC) of high-strength aluminum alloys has been a major problem in the aircraft industry, the possibility of an employment of Al-Li alloys has been considered, taking into account a use of Al-Li-Cu alloys. Attention is given to a research program concerned with the evaluation of the relative SC resistance of two P/M processed Al-Li-Cu alloys. The behavior of the alloys, with and without an addition of magnesium, was studied with the aid of three test methods. The susceptibility to SC was found to depend on the microstructure of the alloys.

  14. Corrosion Studies of 2195 Al-Li Alloy and 2219 Al Alloy with Differing Surface Treatments

    Science.gov (United States)

    Danford, M. D.; Mendrek, M. J.

    1998-01-01

    Corrosion studies of 2195 Al-Li and 2219 Al alloys have been conducted using the scanning reference electrode technique (SRET) and the polarization resistance (PR) technique. The SRET was used to study corrosion mechanisms, while corrosion rate measurements were studied with the PR technique. Plates of Al203 blasted, soda blasted and conversion coated 2219 Al were coated with Deft primer and the corrosion rates studied with the EIS technique. Results from all of these studies are presented.

  15. Effect of aging in an electric field on microstructures and properties of 1420 Al- Li alloy

    Institute of Scientific and Technical Information of China (English)

    刘北兴; 李洪涛; 覃耀春; 冯海波

    2002-01-01

    After solution treatment, the 1420 Al- Li alloy samples were aged at different temperatures in an e-lectric field with different intensity. The measurements made showed that the electric field increased the strengthofthe 1420 Al -Li alloy, and best properties were obtained when they were aged at 120 ℃ with E = 4 kV/cmfor 12 hrs. The electric field promoted the nucleation ofδ' phase, increased the quantity of the δ' phase, andmade the size of the δ' phase particles smaller. The electric field restrained the formation and growth of PFZ,and increased the intensity of the electric field while the width of the PFZ was decreased.

  16. EBSD and Nanoindentation-Correlated Study of Delamination Fracture in Al-Li Alloy 2090

    Science.gov (United States)

    Tayon, Wesley A.; Crooks, Roy E.; Domack, Marcia S.; Wagner, John A.; Elmustafa, A. A.

    2008-01-01

    Al-Li alloys offer attractive combinations of high strength and low density. However, a tendency for delamination fracture has limited their use. A better understanding of the delamination mechanisms may identify methods to control delaminations through processing modifications. A combination of new techniques has been used to evaluate delamination fracture in Al-Li alloys. Both high quality electron backscattered diffraction (EBSD) information and valid nanoindentation measurements were obtained from fractured test specimens. Correlations were drawn between nano-scale hardness variations and local texture along delaminating boundaries. Intriguing findings were observed for delamination fracture through the combined analysis of grain orientation, Taylor factor, and kernel average misorientation.

  17. Effects of Thermal Exposure on Properties of Al-Li Alloys

    Science.gov (United States)

    Shah, Sandeep; Wells, Douglas; Stanton, William; Lawless, Kirby; Russell, Carolyn; Wagner, John; Domack, Marcia; Babel, Henry; Farahmand, Bahram; Schwab, David; Munafo, Paul M. (Technical Monitor)

    2002-01-01

    Aluminum-Lithium (Al-Li) alloys offer significant performance benefits for aerospace structural applications due to their higher specific properties compared with conventional Al alloys. For example, the application of Al-Li alloy 2195 to the space shuffle external cryogenic fuel tank resulted in weight savings of over 7,000 lb, enabling successful deployment of International Space Station components. The composition and heat treatment of 2195 were optimized specifically for strength-toughness considerations for an expendable cryogenic tank. Time-dependent properties related to reliability, such as thermal stability, fatigue, and corrosion, will be of significant interest when materials are evaluated for a reusable cryotank structure. Literature surveys have indicated that there is limited thermal exposure data on Al-Li alloys. The effort reported here was designed to establish the effects of thermal exposure on the mechanical properties and microstructure of Al-Li alloys C458, L277, and 2195 in plate gages. Tensile, fracture toughness, and corrosion resistance were evaluated for both parent metal and friction stir welds (FSW) after exposure to temperatures as high as 300 F for up to 1000 hrs. Microstructural changes were evaluated with thermal exposure in order to correlate with the observed data trends. The ambient temperature parent metal data showed an increase in strength and reduction in elongation after exposure at lower temperatures. Strength reached a peak with intermediate temperature exposure followed by a decrease at highest exposure temperature. Friction stir welds of all alloys showed a drop in elongation with increased length of exposure. Understanding the effect of thermal exposure on the properties and microstructure of Al-Li alloys must be considered in defining service limiting temperatures and exposure times for a reusable cryotank structure.

  18. Assessment of Al-Li Alloys for Cryotanks

    Science.gov (United States)

    Babel, Henry W.; Bozich, William; Farahmand, Bob; DeJesus, Ron; Sankaran, K. K.; Schwab, Dave; Tarkanian, Mike; Funk, Joan G. (Technical Monitor)

    2002-01-01

    This viewgraph presentation provides information on steps undertaken to determine the suitability of Aluminum and Lithium alloys in cryogenic tank construction. Major characteristics are offered for several different candidate alloys including reliability, weldability, flammability, and required thicknesses.

  19. Cryogenic mechanical properties of low density superplastically formable Al-Li alloys

    Science.gov (United States)

    Verzasconi, S. L.; Morris, J. W., Jr.

    1989-01-01

    The aerospace industry is considering the use of low density, superplastically formable (SPF) materials, such as Al-Li alloys in cryogenic tankage. SPF modifications of alloys 8090, 2090, and 2090+In were tested for strength and Kahn tear toughness. The results were compared to those of similar tests of 2219-T87, an alloy currently used in cryogenic tankage, and 2090-T81, a recently studied Al-Li alloy with exceptional cryogenic properties (1-9). With decreasing temperature, all materials showed an increase in strength, while most materials showed an increase in elongation and decrease in Kahn toughness. The indium addition to 2090 increased alloy strength, but did not improve the strength-toughness combination. The fracture mode was predominantly intergranular along small, recrystallized grains, with some transgranular fracture, some ductile rupture, and some delamination on large, unrecrystallized grains.

  20. Dislocation Dynamics in Al-Li Alloys. Mean Jump Distance and Activation Length of Moving Dislocations

    NARCIS (Netherlands)

    Hosson, J.Th.M. De; Huis in 't Veld, A.; Tamler, H.; Kanert, O.

    1984-01-01

    Pulsed nuclear magnetic resonance proved to be a complementary new technique for the study of moving dislocations in Al-Li alloys. The NMR technique, in combination with transmission electron microscopy and strain-rate change experiments have been applied to study dislocation motion in Al-2.2 wt% Li

  1. ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY DURING CORROSION PROCESS OF 8090 Al-Li ALLOY IN EXCO SOLUTION

    Institute of Scientific and Technical Information of China (English)

    J.F. Li; Z.Q. Zheng; C.Y. Tan; S.C. Li; Z. Zhang; J.Q. Zhang

    2004-01-01

    The corrosion behavior and electrochemical impedance spectroscopy ( EIS) features of 8090 Al-Li alloys in EXCO solution were investigated, and the EIS was simulated using an equivalent circuit. At the beginning of immersion in EXCO solution, the EIS is comprised by a depressed capacitive arc at high-mediate frequency and an inductive arc at low frequency, and the inductive component decreases and disappears with immersion time. Once exfoliation or severe pitting corrosion is produced, two capacitivearcs appear in the EIS. These two capacitive arcs are originated from the two parts of the corroded alloy surface, the original flat alloy surface and the new inter-face exposed to the aggressive EXCO solution due to the exfoliation or pitting corrosion.Some corrosion development features of 8090 Al-Li alloys in EXCO solution can be obtained through simulated EIS information.

  2. Aqueous sodium chloride induced intergranular corrosion of Al-Li-Cu alloys

    Science.gov (United States)

    Pizzo, P. P.; Daeschner, D. L.

    1986-01-01

    Two methods have been explored to assess the susceptibility of Al-Li-Cu alloys to intergranular corrosion in aqueous sodium chloride solution. They are: (1) constant extension rate testing with and without alternate-immersion preexposure and (2) metallographic examination after exposure to a NaCl-H2O2 corrosive solution per Mil-H-6088F. Intergranular corrosion was found to occur in both powder and ingot metallurgy alloys of similar composition, using both methods. Underaging rendered the alloys most susceptible. The results correlate to stress-corrosion data generated in conventional time-to-failure and crack growth-rate tests. Alternate-immersion preexposure may be a reliable means to assess stress corrosion susceptibility of Al-Li-Cu alloys.

  3. A new high strength and high tolerance-resistance Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Shou-jie; LU Zheng; DAI Sheng-long; HAN Ya-fang; YAN Ming-gao

    2006-01-01

    In order to develop a new high strength and high tolerance-resistance Al-Li alloy which can be used in aerospace industry,the effects of microalloying elements such as Mg, Ag, Mn and Zn on the mechanical properties of Al-Cu-Li alloys were studied. The results show that the strengthening effects of Mg+Ag and Mg+Zn additions are higher than those of the individual Mg, Ag or Zn addition. The element Mn can also bring some extent strengthening effects on the alloys, but it has nothing to do with the other microalloying elements present or not. Finally, a new Al-Li alloy with Mg+Zn+Mn additions was developed, which possesses high strength and high tolerance-resistance promising properties for aerospace applications.

  4. In Situ Assessment of Lattice in an Al-Li Alloy

    Science.gov (United States)

    Beaudoin, A. J.; Obstalecki, M.; Tayon, W.; Hernquist, M.; Mudrock, R.; Kenesei, P.; Lienert, U.

    2013-01-01

    The lattice strains of individual grains are measured in an Al-Li alloy, AA 2195, using high-energy X-ray diffraction at a synchrotron source. The diffraction of individual grains in this highly textured production alloy was isolated through use of a depth-defining aperture. It is shown that hydrostatic stress, and in turn the stress triaxiality, can vary significantly from grain to grain.

  5. Effect of Rare Earth Elements on Anisotropy and Microstructure of Al-Li Alloy 2195 Sheets

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For the purpose of decreasing the applied limitation resulting from the anisotropic mechanical property of Al-Li alloy 2195, this study employed a complex heat treatment process, involving the pre-tension, thermo-infiltration of the rare earth element Ce, solution treatment, and artificial aging technology. The results indicate that the infiltration of rare earth element Ce benefits the abatement of anisotropy of Al-Li alloy 2195 sheet, in contrast with that of the normal heat treatment process. The gradient of the Vickers-hardness decreases at least 50% through the thickness, and the tensile strength in the rolling direction also increases significantly. If Ce was infiltrated into the alloy under the optimum pre-deformation, the yield strength (σ0.2) increased by 30 MPa while the tensile strength (σb) enhanced by 25 MPa compared to the rare earth free samples. Meanwhile, the fractography illustrated that the fracture surface of the sample became more desirable.

  6. Study on Damage of High Temperature Plastic Deformation for Al-Li Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The security of use for Al-Li alloy will be greatly influenced by the damage degree of plastic deformation within it at high temperature . Based on continuum damage mechanics theory, the damage evolution of Al-5.44Mg-2.15Li-0.12Zr alloy during plastic deforming at high temperature is simulated by using the damage evolution model of high temperature plastic deformation. The changing rule of its inner damage with deformation temperature, strain rate and strain is gained in this paper. The equation of damage evolution for high temperature plastic deformation is developed, providing an academic basis for the technology of plastic process of Al-Li alloys.

  7. Composition and corrosion resistance of cerium conversion films on 2195Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    SONG Dong; FENG Xingguo; SUN Mingren; MA Xinxin; TANG Guangze

    2012-01-01

    The Ce conversion films on 2195Al-Li alloy without and with post-treatment were studied and the corrosion resistance was evaluated as well.The surface morphology was observed by scanning electron microscopy (SEN),and the chemical composition was characterized by X-ray photoelectron spectroscopy (XPS).The corrosion behaviors of 2195Al-Li alloy and conversion coating were assessed by means of potentiodynamic polarization curves.The experimental results indicated that after post-treatment the surface quality was improved significantly.According to XPS,the conversion coating after post-treatment was mainly composed of CeO2,Ce2O3,Ce-OH and a little MoO3 and MoO2.The results of potentiodynamic polarization curves revealed that the conversion coating with post-treatment possessed better corrosion resistance than bare alloy and Ce conversion coating without post-treatment.

  8. Computer Simulation of Ordering and Atom Clustering in Aging Binary Al-Li Alloy

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-ling; CHEN Zheng; WANG Yong-xin; HU Ming-juan

    2004-01-01

    Ordering and atom clustering in aging binary Al-Li alloy has been investigated by computer simulation through calculating the long range order (lro.) parameter and composition deviation order parameter from single-site occupation probabilities of Li atom. The results show that when the alloy lies in metastable region in the phase diagram ordering and atom clustering occur simultaneously. As the composition of the alloy increases ordering occurs earlier than atom clustering gradually. When the alloy lies in instable region atom clustering takes place after the congruent ordering completes. It has also been found that the incubation period of the phase transformation is shortened as the composition increases.

  9. Segregation Study of the β phase on the Al-Li Alloy Surface using Auger Electron Spectroscopy

    Science.gov (United States)

    Belkhiat, S.; Keraghel, F.

    2009-11-01

    Auger Electron spectroscopy (AES) has been used to study lithium segregation on Al-3.49wt%-Li alloy surface. In this work, the surface atomic composition as a function of temperature was followed. In our previous works, the activation energy of Li segregation has been determined experimentally being in agreement with the resulted theoretical value. In this paper, one showed that the segregation energy of Li on the surface depends of the crystalline structure and of the Li content in the Al-Li alloy matrix. β-AlLi phase on the alloy surface, used in the power sources for the propulsion of electrical vehicles and for stocking energy, is obtained by progressive heating. We showed that the segregated lithium on the alloy surface is reversible as a function of decreasing temperature and consequently β-AlLi phase is converted in α-AlLi phase. On the other hand, the brutal heating of the sample drives to the conversion of the α-AlLi phase to β-AlLi phase and stabilizes the surface towards other segregation; therefore the conversion of β-AlLi phase to α-AlLi phase is irreversible.

  10. Li overlayer formation, oxidation and sputtering characteristics of Al-Li alloys and W/Al-Li composites for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, A.R. (Argonne National Lab., IL (USA)); DeWald, A.B.; Scott, P.; Savage, H. (Corium Industries, Inc., Atlanta, GA (USA))

    1990-01-01

    The next generation of long pulse fusion devices will impose severe requirements on the properties of plasma-facing materials. In devices such as ITER, a divertor design is being considered, using a divertor plate which would be either tungsten or a low-Z material such as graphite or beryllium. Strongly segregating lithium alloys have been proposed as a means of producing a self-sustaining low-Z overlayer which lowers plasma Z{sub eff} and resists self-sputtering. Aluminum-lithium alloys are among the better-characterized lithium-bearing alloys, and it has been demonstrated that lithium segregates strongly in aluminum. However, aluminum has a relatively low melting point, and for low lithium concentrations, the lithium diffusion rate is too slow to replenish lithium at the rate at which it is eroded by the incoming plasma. It has been suggested previously that the superionic {beta} phase Al-Li alloy (48--54 at. % Li) should have high enough diffusivity to be able to replenish surface lithium, and that incorporation of the {beta}-phase AlLi in a composite with tungsten would provide high temperature strength and melt layer stability, along with significantly better thermal conductivity than pure tungsten. Such a composite has been fabricated, as well as a variation containing titanium as a means of controlling oxidation at grain boundaries. The Li overlayer formation, erosion, and replenishment are characterized for the {beta}-phase LiAl alloy, and W-AlLi and W-Ti-AlLi composites. It is found that if there is no oxide layer to inhibit the Li segregation, Li diffusion is extremely rapid, and an oxygen-free Li overlayer is formed which is stable under continuous ion beam sputtering. 21 refs., 7 figs.

  11. Solid-solution thermodynamics in Al-Li alloys

    Science.gov (United States)

    Alekseev, A. A.; Lukina, E. A.

    2016-05-01

    The relative equilibrium concentrations of lithium atoms distributed over different electron-structural states has been estimated. The possibility of the existence of various nonequilibrium electron-structural states of Li atoms in the solid solution in Al has been substantiated thermodynamically. Upon the decomposition of the supersaturated solid solution, the supersaturation on three electron-structural states of Li atoms that arises upon the quenching of the alloy can lead to the formation of lithium-containing phases in which the lithium atoms enter in one electron-structural state.

  12. Bulk and Surface Properties of Liquid Al-Li and Li-Zn Alloys

    Science.gov (United States)

    Trybula, Marcela; Gancarz, Tomasz; Gasior, Wladyslaw; Pasturel, Alain

    2014-11-01

    Physicochemical properties like density, surface tension, and viscosity of liquid binary Al-Li and Li-Zn alloys have been measured using draining crucible method. The experimentally measured surface-tension values have been compared to theoretical results based either on the Butler model or the compound formation model assuming the existence of the most favored A 1 B 2 and A 2 B 3 clusters. Several models for viscosity calculation have been also applied and discussed in confrontation with measured data. Finally, the clustering effects in the liquid Al-Li and Li-Zn alloys have been examined using two microscopic functions, i.e., the concentration fluctuation function in the long-wavelength limit and the Warren-Cowley short-range order parameter.

  13. Effect of heat treatments on 8090 AlLi alloy pitting susceptibility in sea water

    Energy Technology Data Exchange (ETDEWEB)

    Beccaria, A.M. [CNR, Genova (Italy). Istituto per la Corrosion Marina dei Metalli; Traverso, P. [CNR, Genova (Italy). Istituto per la Corrosion Marina dei Metalli

    1996-05-01

    The pitting susceptibility of 8090 Al-Li alloy in sea water, after different heat treatments, was investigated. Free corrosion and electrochemical tests were carried out at 25 C, in quiescent sea water at pH=8.2 and dissolved oxygen =6.5 ppm. The microstructure was examined by metallographic microscopy and by X-Ray microdiffractometry, while the corrosion layer was characterized by chemical methods and by Infrared and X-ray photoelectron spectroscopies. The following was observed: . aging treatments lead to a non homogeneous microstructure which increases the average corrosion rate as well as pitting susceptibility; . heat treatments do not affect the average passive film composition; . in all examined states, Al-Li alloy 8090 is subject to localized corrosion which takes place preferentially at the grain boundaries. (orig.)

  14. A surface analytical examination of Stringer particles in Al-Li-Cu alloys

    Science.gov (United States)

    Larson, L. A.; Avalos-Borja, M.; Pizzo, P. P.

    1983-01-01

    A surface analytical examination of powder metallurgy processed Al-Li-Cu alloys was conducted. The oxide stringer particles often found in these alloys was characterized. Particle characterization is important to more fully understand their impact on the stress corrosion and fracture properties of the alloy. The techniques used were SIMS (Secondary Ion Mass Spectroscopy) and SAM (Scanning Auger Microscopy). The results indicate that the oxide stringer particles contain both Al and Li with relatively high Li content and the Li compounds may be associated with the stringer particles, thereby locally depleting the adjacent matrix of Li solute.

  15. Transmission electron microscopy characterization of microstructural features of Al-Li-Cu alloys

    Science.gov (United States)

    Avalos-Borja, M.; Pizzo, P. P.; Larson, L. A.

    1983-01-01

    A transmission electron microscopy (TEM) examination of aluminum-lithium-copper alloys was conducted. The principal purpose is to characterize the nature, size, and distribution of stringer particles which result from the powder metallurgy (P/M) processing of these alloys. Microstructural features associated with the stringer particles are reported that help explain the stress corrosion susceptibility of the powder metallurgy-processed Al-Li-Cu alloys. In addition, matrix precipitation events are documented for a variety of heat treatments and process variations. Hot rolling is observed to significant alter the nature of matrix precipitation, and the observations are correlated with concomitant mechanical property variations.

  16. Effect of Electric Field on Conductivity and Vickers Hardness of an Al-Li Alloy

    Science.gov (United States)

    Liu, Bing; Chen, Da-Rong; Chen, Zheng; Wang, Yong-Xin; Li, Xiao-Ling

    2003-11-01

    Static electric fields were applied on an aluminium-lithium alloy during solution treatment. The conductivity and Vickers hardness of the quenched Al-Li alloy is changed with the effect of electric field. The Vickers hardness increases with the applied electric field for a certain solutionizing time but decreases with the time under an electric field. In the absence of the electric field, the Vickers hardness and the conductivity increase synchronously, while reversed after electric field treatment. Positive and negative electric fields had the similar effect. The change of the local electron density in alloy caused by electric field is presented to explain the effect.

  17. Time-Temperature-Precipitation Behavior in Al-Li Alloy 2195

    Science.gov (United States)

    Chen, P. S.; Bhat, B. N.

    2002-01-01

    Transmission electron microscopy was used to study time-temperature-precipitation (TTP) behavior in aluminum-lithium (Al-Li) 2195 alloy. Al-Li 2195 (nominally Al + 4 percent Cu + 1 percent Li + 0.3 percent Ag + 0.3 percent Mg + 0.1 percent Zr) was initially solutionized for 1 hr at 950 F and then stretched 3 percent. Heat treatments were conducted for up to 100 hr at temperatures ranging from 200 to 1,000 F. TTP diagrams were determined for both matrix and subgrain boundaries. Depending upon heat treatment conditions, precipitate phases (such as GP zone, theta'', theta', theta, delta', T1, TB, and T2) were found in the alloy. The TTP diagrams were applied as a guide to avoid T1 precipitation at subgrain boundaries, as part of an effort to improve the alloy's cryogenic fracture toughness (CFT). New understanding of TTP behavior was instrumental in the development of a two-step artificial aging treatment that significantly enhanced CFT in Al-Li 2195.

  18. Thermal Exposure Effects on Properties of Al-Li Alloy Plate Products

    Science.gov (United States)

    Shah, Sandeep; Wells, Douglas; Wagner, John; Babel, Henry

    2002-01-01

    Aluminum-Lithium (AL-Li) alloys offer significant performance benefits for aerospace structural applications due to their higher specific properties compared with conventional aluminum alloys. For example, the application of an Al-Li alloy to the space shuttle external cryogenic fuel tank contributed to the weight savings that enabled successful deployment of International Space Station components. The composition and heat treatment of this alloy were optimized specifically for strength-toughness considerations for an expendable cryogenic tank. Time dependent properties related to reliability, such as thermal stability, fatigue, and corrosion, will be of significant interest when materials are evaluated for a reusable cryotank structure. As most aerospace structural hardware is weight sensitive, a reusable cryotank will be designed to the limits of the materials mechanical properties. Therefore, this effort was designed to establish the effects of thermal exposure on the mechanical properties and microstructure of one relatively production mature alloy and two developmental alloys C458 and L277. Tensile and fracture toughness behavior was evaluated after exposure to temperatures as high as 3oooF for up to IO00 hrs. Microstructural changes were also evaluated to correlate with the observed data trends. The ambient temperature parent metal data showed an increase in strength and reduction in elongation after exposure at lower temperatures. Strength reached a peak with intermediate temperature exposure followed by a decrease at highest exposure temperature. Characterizing the effect of thermal exposure on the properties of Al-Li alloys is important to defining a service limiting temperature, exposure time, and end-of-life properties.

  19. A Study of Friction Stir Welded 2195 Al-Li Alloy by the Scanning Reference Electrode Technique

    Science.gov (United States)

    Donford, M. D.; Ding, R. J.

    1998-01-01

    A study of the corrosion of friction stir welded 2195 Al-Li alloy has been carried out using the scanning reference electrode technique (SRET). The results are compared to those obtained from a study of heterogeneously welded samples.

  20. Structure and Mechanical Properties of Al-Li Alloys as Cast

    Directory of Open Access Journals (Sweden)

    J. Augustyn-Pieniążek

    2013-04-01

    Full Text Available The high mechanical properties of the Al-Li-X alloys contribute to their increasingly broad application in aeronautics, as an alternative for the aluminium alloys, which have been used so far. The aluminium-lithium alloys have a lower specific gravity, a higher nucleation and crack spread resistance, a higher Young’s module and they characterize in a high crack resistance at lower temperatures. The aim of the research planned in this work was to design an aluminium alloy with a content of lithium and other alloy elements. The research included the creation of a laboratorial melt, the microstructure analysis with the use of light microscopy, the application of X-ray methods to identify the phases existing in the alloy, and the microhardness test.

  1. The effects of zinc addition on the environmental stability of Al-Li alloys

    Science.gov (United States)

    Kilmer, Raymond J.; Stoner, Glenn E.

    1990-01-01

    It was found that relatively small addition of Zn can improve the stress corrosion cracking (SCC) resistance of Al-Li alloys. However, the mechanism by which this is accomplished is unclear. The role that Zn plays in altering the behavior of Alloy 8090 is investigated. Early results suggest that Zn additions increase the volume fraction of delta(Al3Li) precipitation and differential scanning calorimetry (DSC) on these alloys confirms this. The four alloys studied each had initial compositions lying in the 8090 window and had varying amounts of Zn added to them. Alloy 8090, like other Al-Li alloys, displays a delta' precipitate free zone (PFZ) upon artificial aging along the grain and subgrain boundaries. However Zn additions greatly decreased or eliminated a delta' PFZ after 100 hours at 160 C. This implies that the subgrain boundary precipitation kinetics are being altered and suppressed. Furthermore, there appears to be a window of Zn concentration above which a delta ' PFZ can reappear with the nucleation and growth of a currently unidentified precipitate on the boundaries. Polarization experiments were performed and the results presented. The experiments were performed in deaerated 3.5 w/o NaCl in both as received (T3) condition and at peak aging of 100 hours at 160 C. The aging profile was determined via Vickers Hardness tests.

  2. Effects of Magnetic Field on Fracture of Al-Li Alloy Containing Cerium

    Institute of Scientific and Technical Information of China (English)

    刘兵; 王西宁; 陈铮

    2003-01-01

    The effects of magnetic field on fracture feature and microstructure of Al-Li alloys containing Ce were investigated. Experiment results show that the fracture features and the microstructures are changed with the magnetic field. The fracture surface of the alloys is mainly quasi-cleavage without applying magnetic field. With a magnetic field, the fracture of quasi-cleavage changes to more secondary cracks and less quasi-cleavage plates on fracture surface. Grains become thinner and uniform with applying magnetic field. The influence of magnetic field on atom diffusion was discussed.

  3. Intrinsic fatigue crack growth rates for Al-Li-Cu-Mg alloys in vacuum

    Science.gov (United States)

    Slavik, D. C.; Blankenship, C. P., Jr.; Starke, E. A., Jr.; Gangloff, R. P.

    1993-01-01

    The influences of microstructure and deformation mode on inert environment intrinsic fatigue crack propagation were investigated for Al-Li-Cu-Mg alloys AA2090, AA8090, and X2095 compared to AA2024. The amount of coherent shearable delta-prime (Al3Li) precipitates and extent of localized planar slip deformation were reduced by composition (increased Cu/Li in X2095) and heat treatment (double aging of AA8090). Intrinsic growth rates, obtained at high constant K(max) to minimize crack closure and in vacuum to eliminate any environmental effect, were alloy dependent; da/dN varied up to tenfold based on applied Delta-K or Delta-K/E. When compared based on a crack tip cyclic strain or opening displacement parameter, growth rates were equivalent for all alloys except X2095-T8, which exhibited unique fatigue crack growth resistance. Tortuous fatigue crack profiles and large fracture surface facets were observed for each Al-Li alloy independent of the precipitates present, particularly delta-prime, and the localized slip deformation structure. Reduced fatigue crack propagation rates for X2095 in vacuum are not explained by either residual crack closure or slip reversibility arguments; the origin of apparent slip band facets in a homogeneous slip alloy is unclear.

  4. The stress-corrosion behavior of Al-Li-Cu alloys: A comparison of test methods

    Science.gov (United States)

    Rizzo, P. P.; Galvin, R. P.; Nelson, H. G.

    1982-01-01

    Two powder metallurgy processed (Al-Li-Cu) alloys with and without Mg addition were studied in aqueous 3.5% NaCl solution during the alternate immersion testing of tuning fork specimens, slow crack growth tests using fracture mechanics specimens, and the slow strain rate testing of straining electrode specimens. Scanning electron microscopy and optical metallography were used to demonstrate the character of the interaction between the Al-Li-Cu alloys and the selected environment. Both alloys are susceptible to SC in an aqueous 3.5% NaCl solution under the right electrochemical and microstructural conditions. Each test method yields important information on the character of the SC behavior. Under all conditions investigated, second phase particles strung out in rows along the extrusion direction in the alloys were rapidly attacked, and played principal role in the SC process. With time, larger pits developed from these rows of smaller pits and under certain electrochemical conditions surface cracks initiated from the larger pits and contributed directly to the fracture process. Evidence to support slow crack growth was observed in both the slow strain rate tests and the sustained immersion tests of precracked fracture mechanics specimens. The possible role of H2 in the stress corrosion cracking process is suggested.

  5. Improving fatigue property of Al-Li alloy by thermo-mechanical treatment

    Institute of Scientific and Technical Information of China (English)

    丁剑; 张荻; 范同祥; 吕维洁; 覃继宁

    2003-01-01

    Tension-compression fatigue test was performed to study the effect of the cold working + ageing treatment on the fatigue property of Al-Li alloy under stress-controlled condition. The main results show that: fatigue strength of specimen is improved obviously after cold working + ageing treatment; compared to the simple ageing treatment, the necessary ageing time can be reduced apparently to reach the peak-ageing strengthening effect; the fatigue strength of specimen cut from the vertical direction to cold working direction is higher than that cut from the parallel direction.

  6. Microstructure and low-temperature plastic deformation of Al-Li alloy

    Science.gov (United States)

    Isaev, N. V.; Zabrodin, P. A.; Spuskanyuk, V. Z.; Davydenko, A. A.; Pustovalov, V. V.; Fomenko, V. S.; Braude, I. S.

    2012-01-01

    Features of the plastic deformation of solid Al-Li solutions with microstructures formed by direct and angular hydroextrusion are studied under tension at temperatures of 4.2-350 K. It is found that the grain size reductions, increases in the average density of defects, and changes in the orientational textures during combined hydroextrusion lead to increased strength and reduced plasticity of the microcrystalline alloy relative to initially large-grained samples. The high yield stress of the microcrystalline alloy is explained by a higher grain density and the evolution of an orientational texture. The strong temperature dependence of the yield stress is typical of thermally activated interactions between dislocations and local obstacles in the form of deformation defects produced during hydroextrusion. The low plasticity of the microcrystalline alloy, which already shows up as a localization of plastic deformation with small deformations, is caused by a low rate of work hardening owing to enhanced dynamic recovery of fine grains even at low temperatures. The rate of dynamic recovery decreases, while uniform deformation increases, at temperatures of 77 K and below. Based on data on the high stress rate sensitivity at temperatures above 77 K and the low activation volume for plastic deformation of microcrystalline Al-Li, it is proposed that high-angle grain boundaries may serve as highly efficient sources and sinks of mobile dislocations.

  7. A positron study on the microstructural evolution of Al-Li based alloys in the early stages of plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Diego, N. de; Rio, J. del [Univ. Complutense, Madrid (Spain). Dept. de Fisica de Materiales; Romero, R.; Somoza, A. [Univ. Nacional del Centro de la Provincia de Buenos Aires, Tandil (Argentina). Inst. de Fisica de Materiales]|[Comision de Investigaciones Cientificas de la Provincia de Buenos Aires (Argentina)

    1997-11-01

    The formation of voids by coalescence of microvoids initiated at precipitates has been proposed to explain the fracture mechanisms in alloys containing a large number of second phase particles whereas in binary Al-Li alloys with shearable particles the brittleness could be linked with the grain boundary fracture. Most of the microstructure studies of Al-Li alloys have been performed by deforming to fracture; however, little is known about the processes and mechanisms involved in the early stages of plastic deformation. Butler et al. have studied a quaternary Al-Li alloy and have found that there is a critical effective strain to cause voiding, which is about 0.06 and 0.1% for the aged and for the solution treated material respectively. It is very well established that positrons are very sensitive to vacancy-like defects. With the aim of clarifying the behavior of Al-Li based alloys in the very early stages of deformation, and detecting the eventual formation of microvoids, the authors have studied the response of the positron lifetime parameters to the degrees of deformation in age-hardenable Al-Li based alloys plastically deformed under tensile stress.

  8. On the intergranular fracture behavior of high-temperature plastic deformation of 1420 Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The tensile deformation hot simulation test of as-cast 1420 Al-Li alloy was performed on Gleeble-1500 Thermal Simulator in the deformation temperature range from 350 to 450 ℃, and the strain rate range from 0.01 to 10.0 s-1.The tensile fracture behavior of the 1420 Al-Li alloy at high temperature was studied experimently. The results show that the tensile fracture mode of the 1420 Al-Li alloy at high temperature is changed from typical transgranular ductile fracture to intergranular brittle fracture with the increase of the deformation temperature and the strain rate. It is made out that the precipitation of LiH is the fundamental reason for the intergranular brittle fracture of the 1420 Al-Li alloy at high temperature. The mechanism of hydrogen embrittlement of the 1420 Al-Li alloy at high temperature was discussed, and it was proposed that the hydrogen embrittlement at high temperature is an integrated function of the dynamic and the static force, which enrichs the theories of hydrogen embrittlement.

  9. Mechanistic Study of Delamination Fracture in Al-Li Alloy C458 (2099)

    Science.gov (United States)

    Tayon, W. A.; Crooks, R. E.; Domack, M. S.; Wagner, J. A.; Beaudoin, A. J.; McDonald, R. J.

    2009-01-01

    Delamination fracture has limited the use of lightweight Al-Li alloys. In the present study, electron backscattered diffraction (EBSD) methods were used to characterize crack paths in Al-Li alloy C458 (2099). Secondary delamination cracks in fracture toughness samples showed a pronounced tendency for fracture between grain variants of the same deformation texture component. These results were analyzed by EBSD mapping methods and simulated with finite element analyses. Simulation procedures include a description of material anisotropy, local grain orientations, and fracture utilizing crystal plasticity and cohesive zone elements. Taylor factors computed for each grain orientation subjected to normal and shear stresses indicated that grain pairs with the largest Taylor factor differences were adjacent to boundaries that failed by delamination. Examination of matching delamination fracture surface pairs revealed pronounced slip bands in only one of the grains bordering the delamination. These results, along with EBSD studies, plasticity simulations, and Auger electron spectroscopy observations support a hypothesis that delamination fracture occurs due to poor slip accommodation along boundaries between grains with greatly differing plastic response.

  10. Exfoliation corrosion susceptibility of 8090 Al-Li alloy examined by electrochemical impedance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    蔡超; 李劲风; 郑子樵; 张昭

    2004-01-01

    The exfoliation corrosion susceptibility and electrochemical impedance spectroscopy(EIS) of rolled and peak-aged 8090 Al-Li alloys in EXCO solution were studied, and the EIS after exfoliation was simulated. Once exfoliation occurs, two capacitive arcs appear in the EIS at high-mediate frequency and mediate-low frequency respective ly. The exfoliation-attacked alloy surface consists of two parts, an original flat alloy surface and a new inter-face exposed to EXCO solution due to the exfoliation. The capacitance corresponding to the new exfoliation inter-face in creases approximately linearly with time at early exfoliation stage, due to the enlargement of the new inter-face. Then it maintains stable, due to the corrosion product covering on the new inter-face. The exfoliation susceptibility can be judged through the average slope of the capacitance vs time curve of the early exfoliation stage. This average slope of the rolled 8090 alloy is much higher than that of the peak-aged 8090 alloy, accordingly the rolled 8090 alloy is more susceptible to exfoliation than the peak-aged 8090 alloy.

  11. Microstructure and Mechanical Properties of an Al-Li-Mg-Sc-Zr Alloy Subjected to ECAP

    Directory of Open Access Journals (Sweden)

    Anna Mogucheva

    2016-10-01

    Full Text Available The effect of post-deformation solution treatment followed by water quenching and artificial aging on microstructure and mechanical properties of an Al-Li-Mg-Sc-Zr alloy subjected to equal-channel angular pressing (ECAP was examined. It was shown that the deformed microstructure produced by ECAP remains essentially unchanged under solution treatment. However, extensive grain refinement owing to ECAP processing significantly affects the precipitation sequence during aging. In the aluminum-lithium alloy with ultrafine-grained (UFG microstructure, the coarse particles of the S1-phase (Al2LiMg precipitate on high-angle boundaries; no formation of nanoscale coherent dispersoids of the δ′-phase (Al3Li occurs within grain interiors. Increasing the number of high-angle boundaries leads to an increasing portion of the S1-phase. As a result, no significant increase in strength occurs despite extensive grain refinement by ECAP.

  12. Investigation of exfoliation corrosion of rolled AA8090 Al-Li alloy using electrochemical impedance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    李劲风; 张昭; 曹发和; 程英亮; 张鉴清; 曹楚南

    2003-01-01

    The exfoliation morphologies and electrochemical impedance spectroscopy (EIS) features of as-received rolled AA8090 Al-Li alloy in EXCO solution were studied. The EIS was simulated using an equivalent circuit. The results show that once the exfoliation occurs, the EIS is composed of two capacitive arcs at high frequency and mediate-low frequency; among them, the capacitance corresponding to high frequency (C1) is originated from original flat alloy surface, while the capacitance corresponding to mediate-low frequency (C2) from new interface exposed to EXCO solution due to the exfoliation and the ratio of C2 to C1 increases with exfoliation degree. It is advanced that the exfoliation degree can be quantitatively judged through this ratio.

  13. Influence of Electric Field on Mechanical Properties of Al-Li Alloy Containing Cerium and Electronic Mechanism

    Institute of Scientific and Technical Information of China (English)

    刘兵; 陈铮; 王永欣; 王西宁

    2001-01-01

    The effect of electric field on the mechanical properties and microstructure of Al-Li alloy containing Ce was investigated, and mechanism was discussed. The experimental results show that the ductility of the alloy is enhanced by the electric field. The fracture features are changed and the precipitates are dispersed under the effect of the electric field. The mechanism discussion reveals that the effects of the electric field on the alloy are due to the change of the electron density in the alloy.

  14. Al-Li alloy AA2198's very high cycle fatigue crack initiation mechanism and its fatigue thermal effect

    Science.gov (United States)

    Xu, Luopeng; Cao, Xiaojian; Chen, Yu; Wang, Qingyuan

    2015-10-01

    AA2198 alloy is one of the third generation Al-Li alloys which have low density, high elastic modulus, high specific strength and specific stiffness. Compared With the previous two generation Al-Li alloys, the third generation alloys have much improved in alloys strength, corrosion resistance and weldable characteristic. For these advantages, the third generation Al-Li alloys are used as aircraft structures, such as C919 aviation airplane manufactured by China and Russia next generation aviation airplane--MS-21. As we know, the aircraft structures are usually subjected to more than 108 cycles fatigue life during 20-30 years of service, however, there is few reported paper about the third generation Al-Li alloys' very high cycle fatigue(VHCF) which is more than 108 cycles fatigue. The VHCF experiment of AA2198 have been carried out. The two different initiation mechanisms of fatigue fracture have been found in VHCF. The cracks can initiate from the interior of the testing material with lower stress amplitude and more than 108 cycles fatigue life, or from the surface or subsurface of material which is the dominant reason of fatigue failures. During the experiment, the infrared technology is used to monitor the VHCF thermal effect. With the increase of the stress, the temperature of sample is also rising up, increasing about 15 °C for every 10Mpa. The theoretical thermal analysis is also carried out.

  15. Effects of Annealing Process on the Formability of Friction Stir Welded Al-Li Alloy 2195 Plates

    Science.gov (United States)

    Chen, Po-Shou; Bradford, Vann; Russell, Carolyn

    2011-01-01

    Large rocket cryogenic tank domes have typically been fabricated using Al-Cu based alloys like Al-Cu alloy 2219. The use of aluminum-lithium based alloys for rocket fuel tank domes can reduce weight because aluminum-lithium alloys have lower density and higher strength than Al-Cu alloy 2219. However, Al-Li alloys have rarely been used to fabricate rocket fuel tank domes because of the inherent low formability characteristic that make them susceptible to cracking during the forming operations. The ability to form metal by stretch forming or spin forming without excessive thinning or necking depends on the strain hardening exponent "n". The stain hardening exponent is a measure of how rapidly a metal becomes stronger and harder. A high strain hardening exponent is beneficial to a material's ability to uniformly distribute the imposed strain. Marshall Space Flight Center has developed a novel annealing process that can achieve a work hardening exponent on the order of 0.27 to 0.29, which is approximately 50% higher than what is typically obtained for Al-Li alloys using the conventional method. The strain hardening exponent of the Al-Li alloy plates or blanks heat treated using the conventional method is typically on the order of 0.17 to 0.19. The effects of this novel annealing process on the formability of friction stir welded Al-Li alloy blanks are being studied at Marshall Space Flight Center. The formability ratings will be generated using the strain hardening exponent, strain rate sensitivity and forming range. The effects of forming temperature on the formability will also be studied. The objective of this work is to study the deformation behavior of the friction stir welded Al-Li alloy 2195 blank and determine the formability enhancement by the new annealing process.

  16. Effect of current pulses on fracture morphology in superplastic deformation of 2091 Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The effect of current pulses on the fracture morphology in the superplastic deformation of 2091 AlLi alloy at two kinds of initial strain rate ((ε)1 = 3.33 × 10 -3 s-1;(ε)2= 3.33 × 10-2 s- 1 ) was investigated. Experimental results show that current pulse turns fracture of superplastic deformation at low strain rate from local interior fracture morphology to typical fracture by growth and interlinkage of cavities, and at high strain rate from rough grain boundary surface to smooth grain boundary surface. It is indicated that the characteristic, that current pulse promotes atomic diffusion, maintains an equiaxial grain microstructure at low strain rate, and accelerates the development of diffusional type of cavity and relaxes stress concentration at triple junction of grain boundaries at high strain rate, and makes the superplastic deformation at two kinds of strain rate show a normal superplastic fracture morphology.

  17. Influence of grain orientations on the initiation of fatigue damage in an Al-Li alloy.

    Science.gov (United States)

    Taylor; Zhai; Wilkinson; Martin

    1999-09-01

    The variation in microstructure and texture in a rectangular bar extruded from a billet of spray-cast 8090 Al-Li alloy has been examined. The fine grain size of the as sprayed billet and the moderate extrusion ratio ( approximately 25 : 1) were seen to cause geometric dynamic recrystallization (GDR) in regions of higher strain towards the edge of the bar. The grain morphology varied from the expected elongated grains at the centre of the bar to equiaxed grains where GDR occurred at the bar edges. A + double fibre texture, significantly distorted towards rolling components and varying through the bar thickness, was found using electron backscatter diffraction. Fatigue resulted in a high density of short secondary cracks, many of which had arrested at grain boundaries. The cracks preferentially nucleated in grains from the fibre texture corresponding to high Schmid factors.

  18. Effect of two-stage aging on superplasticity of Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    LUO Zhi-hui; ZHANG Xin-ming; DU Yu-xuan; YE Ling-ying

    2006-01-01

    The effect of two-stage aging on the microstructures and superplasticity of 01420 Al-Li alloy was investigated by means of OM, TEM analysis and stretching experiment. The results demonstrate that the second phase particles distributed more uniformly with a larger volume fraction can be observed after the two-stage aging (120 ℃, 12 h+300 ℃, 36 h) compared with the single-aging(300 ℃, 48 h). After rolling and recrystallization annealing, fine grains with size of 8-10 μm are obtained, and the superplastic elongation of the specimens reaches 560% at strain rate of 8×10-4 s-1 and 480 ℃. Uniformly distributed fine particles precipitate both on grain boundaries and in grains at lower temperature. When the sheet is aged at high temperature, the particles become coarser with a large volume fraction.

  19. Strength and microstructure of 2091 Al-Li alloy TIG welded joint

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The microstructure and tensile properties of TIG welding joints of 2091 Al-Li alloy were investigated both in as-welded and different postweld heat treatment condition. The results show that solution strengthening played an important role in the as-welded condition, though the precipitation strengthening δ' phase formed already in the as-welded weld metal, but its effect was not apparent due to the lower volume fraction of δ' phase. So the strength coefficient (φ) of the welded joint/base metal was 64%. After artificially aging heat treatment, the precipitation strengthening effect increased much due to the formation of more δ' phase and s' phase. Its φ value was increased up to 89%. The highest strength of the welded joints was obtained after solid solution and then artificially aged heat treatment. Due to the proper size of precipitation strengthening phases and their well distribution, the φ value was increased up to 98%.

  20. Comparative Analysis of Al-Li Alloy and Aluminum Honeycomb Panel for Aerospace Application by Structural Optimization

    Directory of Open Access Journals (Sweden)

    Naihui Yu

    2015-01-01

    Full Text Available Al-Li alloy and aluminum honeycomb panel (AHP are both excellent materials for aeronautical structures. In this paper, a plate-type aeronautical structure (PAS, which is a base mounting structure for 172 kg functional devices, is selected for comparative analysis with different materials. To compare system-level performance under multidisciplinary constraints, mathematical models for optimization are established and then structural optimization is carried out using Altair OptiStruct. For AHP, its honeycomb core is regarded as orthotropic material and its mechanical properties are calculated by Allen’s model in order to establish finite element model (FEM. The heights of facing sheet and honeycomb core are selected as design variables for size optimization. For Al-Li alloy plate, topology optimization is carried out to obtain its most efficient load path; and then a reconstruction process is executed for practical manufacturing consideration; to obtain its final configuration, accurate size optimization is also used for reconstructed model of Al-Li alloy plate. Finally, the optimized mass and performance of two PASs are compared. Results show that AHP is slightly superior to Al-Li alloy.

  1. Strength distribution of fatigue crack initiation sites in an Al-Li alloy

    Science.gov (United States)

    Zhai, T.

    2006-10-01

    The stress-number of cycles to failure (S-N) curves were measured along the short-transverse (S) and rolling (L) directions of a hot-cross-rolled AA 8090 Al-Li alloy plate (45-mm thick). The alloy was solution heat treated, quenched in water, strained by 6 pct, and peak aged. Fatigue tests were carried out in four-point bend at room temperature, 20 Hz, R=0.1, in air. It was found that the fatigue limits in the S and L directions were 147 and 197 MPa, respectively. The crack population on the surface of a sample at failure increased with the applied stress level and was found to be a Weibull function of the applied maximum stress in this alloy. The strength distribution of fatigue weakest links, where cracks were initiated, was derived from the Weibull function determined by the experimental data. The fatigue weakest-link density was defined as the crack population per unit area at a stress level close to the ultimate tensile stress and can be regarded as a materials property. The density and strength distribution of fatigue weakest links were found to be markedly different between the L and S directions, accounting for the difference in fatigue limit between the directions in this alloy. They were also found to be different between S-L and S-T samples, and between L-T and L-S samples of this alloy, which could not be revealed by the corresponding S-N curves measured. These differences were due to the anisotropy of the microstructures in different directions in this alloy.

  2. Hot Deformation Behavior and Processing Maps of 2099 Al-Li Alloy

    Science.gov (United States)

    Chen, Bin; Tian, Xiao-lin; Li, Xiao-ling; Lu, Chen

    2014-06-01

    Hot deformation behavior and processing maps of the 2099 Al-Li alloy are investigated by tensile test at the temperature range from 250 to 450 °C and the strain rate range from 0.001 to 5.0 s-1. The typical true stress-true strain curves show that the flow stress increases with increasing the strain rate and decreasing the deforming temperature. All curves exhibit rapid work hardening at an initial stage of strain followed by remarkable dynamic softening. Based on the flow stress behavior, the processing maps are calculated and analyzed according to the dynamic materials model (DMM). The processing maps exhibit an instability domain in the temperature and strain rate ranges: T = 250-260 °C and = 0.1-0.5 s-1. The maps also exhibit an optimum hot working condition in the stability domain that occurs in the temperature of 400 °C for a strain rate of 0.001 s-1 and having a maximum efficiency of 60%. The microstructural examinations exhibit the occurrence of dynamic recovery (DRV) during hot deformation of the 2099 alloy which is the dominant softening mechanism in the alloy. The fracture behavior changes from a brittle fracture to a ductile fracture as strain rate decreases and temperature increases.

  3. Structure-Property Correlations in Al-Li Alloy Integrally Stiffened Extrusions

    Science.gov (United States)

    Hales, Stephen J.; Hafley, Robert A.

    2001-01-01

    The objective of this investigation was to establish the relationship between mechanical property anisotropy, microstructure and crystallographic texture in integrally 'T'-stiffened extruded panels fabricated from the Al-Li alloys 2195, 2098 and 2096. In-plane properties were measured as a function of orientation at two locations in the panels, namely mid-way between (Skin), and directly beneath (Base), the integral 'T' stiffeners. The 2195 extrusion exhibited the best combination of strength and toughness, but was the most anisotropic. The 2098 extrusion exhibited lower strength and comparable toughness, but was more isotropic than 2195. The 2096 extrusion exhibited the lowest strength and poor toughness, but was the most isotropic. All three alloys exhibited highly elongated grain structures and similar location-dependent variations in grain morphology. The textural characteristics comprised a beta + fiber texture, similar to rolled product, in the Skin regions and alpha + fiber texture, comparable to axisymmetric extruded product, in the Base regions. In an attempt to quantitatively correlate texture with yield strength anisotropy, the original 'full constraint' Taylor model and a variant of the 'relaxed constraint' model, explored by Wert et al., were applied to the data. A comparison of the results revealed that the Wert model was consistently more accurate than the Taylor model.

  4. Stress Concentration and Fracture at Inter-variant Boundaries in an Al-Li Alloy

    Science.gov (United States)

    Crooks, Roy; Tayon, Wes; Domack, Marcia; Wagner, John; Beaudoin, Armand

    2009-01-01

    Delamination fracture has limited the use of lightweight Al-Li alloys. Studies of secondary, delamination cracks in alloy 2090, L-T fracture toughness samples showed grain boundary failure between variants of the brass texture component. Although the adjacent texture variants, designated B(sub s1) and B(sub s2), behave similarly during rolling, their plastic responses to mechanical tests can be quite different. EBSD data from through-thickness scans were used to generate Taylor factor maps. When a combined boundary normal and shear tensor was used in the calculation, the delaminating grains showed the greatest Taylor Factor differences of any grain pairs. Kernel Average Misorientation (KAM) maps also showed damage accumulation on one side of the interface. Both of these are consistent with poor slip accommodation from a crystallographically softer grain to a harder one. Transmission electron microscopy was used to confirm the EBSD observations and to show the role of slip bands in the development of large, interfacial stress concentrations. A viewgraph presentation accompanies the provided abstract.

  5. Artifacts introduced by ion milling in Al-Li-Cu alloys.

    Science.gov (United States)

    Singh, A K; Imam, M A; Sadananda, K

    1988-04-01

    Ion milling is commonly used to prepare specimens for observation under transmission electron microscope (TEM). This technique sometimes introduces artifacts in specimens contributing to misleading interpretation of TEM results as observed in the present investigation of Al-Li-Cu alloys. This type of alloy, in general, contains several kinds of precipitates, namely delta', T1, and theta'. It is found that ion milling even for a short time produces drastic changes in the precipitate characteristics as compared to standard electropolishing methods of specimen preparation for TEM. Careful analysis of selected area diffraction patterns and micrographs shows that after ion milling delta' precipitates are very irregular, whereas other precipitates coarsen and they are surrounded by misfit dislocations. In situ hot-stage TEM experiments were performed to relate the microstructure to that observed in the ion-milled specimen. Results and causes of ion milling effects on the microstructure are discussed in relation to standard electropolishing techniques and in situ hot-stage experiment.

  6. Effect of cold compression on precipitation and conductivity of an Al-Li-Cu alloy.

    Science.gov (United States)

    Khan, A K; Robinson, J S

    2008-12-01

    Transmission electron microscopy has been used to investigate the effect of increasing the degree of deformation applied by cold compression on the ageing kinetics and electrical conductivity response of an Al-Li-Cu alloy containing Mg and Ag. When cold compressed greater than 3%, the increased dislocation density accelerates the widespread precipitation of the T(1) phase resulting in an enhanced age hardening response. The lengthening rate of T(1) precipitates is also reduced in this cold compressed condition owing to the reduced local solute supersaturation, a result of the widespread precipitation of T(1) plates. Cold compression by less than 3% does not increase the age hardening response, and the precipitation of GP zones/theta'' appears to be suppressed. Precipitation of the T(1) phase is also not significantly enhanced compared with that of the more than 3% cold compressed conditions. The anomalous decrease in electrical conductivity is associated with the nucleation and growth of the T(1) phase. Strain fields around T(1) precipitates combined with the increased volume fraction of T(1) are thought to be the cause of the anomalous conductivity behaviour.

  7. Evolution of grain structure in AA2195 Al-Li alloy plate during recrystallization

    Institute of Scientific and Technical Information of China (English)

    DU Yu-xuan; ZHANG Xin-ming; YE Ling-ying; LIU Sheng-dan

    2006-01-01

    The evolution of the grain structures in AA2195 Al-Li alloy plate warm-rolled by 80% reduction during recrystallization annealing at 500 ℃ was investigated by electron backscatter diffraction, scanning electron microscopy and transmission electron microscopy. It is found that the elongated grain structures are caused by the lamellar distribution of recrystallization nucleation sites,being lack of large second phase particles (> 1 μm), and dispersive coherent particles (such as δ'andβ) concentrated in planar bands.The recrystallization process may be separated into three stages: firstly, recrystallization nucleation occurs heterogeneously, and the nuclei are concentrated in some planar zones parallel to rolling plane. Secondly, the grain boundaries interacted with small particles concentrate in planar bands, which is able to result in the elongated grain structures. The rate of the grain growth is controlled by the dissolution of these small particles. Thirdly, after most of small particles are dissolved, their hindrance to migration of the grain boundaries fades away, and the unrecrystallized zones are consumed by adjacent recrystallized grains. The migration of high angle grain boundaries along normal direction leads a gradual transformation from the elongated grains to the nearly equiaxed, which is driven by the tension of the grain boundaries.

  8. Duct and cladding alloy

    Science.gov (United States)

    Korenko, Michael K.

    1983-01-01

    An austenitic alloy having good thermal stability and resistance to sodium corrosion at 700.degree. C. consists essentially of 35-45% nickel 7.5-14% chromium 0.8-3.2% molybdenum 0.3-1.0% silicon 0.2-1.0% manganese 0-0.1% zirconium 2.0-3.5% titanium 1.0-2.0% aluminum 0.02-0.1% carbon 0-0.01% boron and the balance iron.

  9. Electrochemical Codeposition of Al-Li-Mg Alloys at Solid Aluminum Electrode from LiCl-KCl-MgCl2 Molten Salt System

    Science.gov (United States)

    Ye, Ke; Zhang, Mi Lin; Chen, Ye; Han, Wei; de Yan, Yong; Cao, Peng

    2010-06-01

    The electrochemical codeposition of Mg and Li at an aluminium electrode in LiCl-KCl (50:50 wt pct) melts containing different concentrations of MgCl2 at 893 K (620 °C) to form Al-Li-Mg alloys was investigated. Cyclic voltammograms showed that the potential of Li metal deposition at an Al electrode, before the addition of MgCl2, is more positive than that of Li metal deposition at an Mo electrode, which indicated the formation of an Al-Li alloy. The underpotential deposition of magnesium at an aluminium electrode leads to the formation of Al-Mg alloys, and the succeeding underpotential deposition of lithium on predeposited Al-Mg alloys leads to the formation of Al-Li-Mg alloys. Chronopotentiometric measurements indicated that the codeposition of Mg and Li occurs at current densities lower than -0.668 A cm-2 in LiCl-KCl-MgCl2 (8 wt pct) melts at an aluminium electrode. The chronoamperometric studies indicated that the onset potential for the codeposition of Mg and Li is -2.000 V, and the codeposition of Mg and Li at an aluminium electrode is formed into Al-Li-Mg alloys when the applied potentials are more negative than -2.000 V. X-ray diffraction and inductively coupled plasma analysis indicated that Al-Li-Mg alloys with different lithium and magnesium contents were prepared via potentiostatic and galvanostatic electrolysis. The microstructure of typical dual phases of the Al-Li-Mg alloy was characterized by an optical microscope and by scanning electron microscopy. The analysis of energy dispersive spectrometry showed that the elements of Al and Mg distribute homogeneously in the Al-Li-Mg alloy. The lithium and magnesium contents of Al-Li-Mg alloys can be controlled by MgCl2 concentrations and by electrolytic parameters.

  10. Environmental fatigue of an Al-Li-Cu alloy. Part 2: Microscopic hydrogen cracking processes

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1992-01-01

    Based on a fractographic analysis of fatigue crack propagation (FCP) in Al-Li-Cu alloy 2090 stressed in a variety of inert and embrittling environments, microscopic crack paths are identified and correlated with intrinsic da/dN-delta K kinetics. FCP rates in 2090 are accelerated by hydrogen producing environments (pure water vapor, moist air, and aqueous NaCl), as defined in Part 1. For these cases, subgrain boundary fatigue cracking (SGC) dominates for delta K values where the crack tip process zone, a significant fraction of the cyclic plastic zone, is sufficiently large to envelop 5 micron subgrains in the unrecrystallized microstructure. SGC may be due to strong hydrogen trapping at T1 precipitates concentrated at sub-boundaries. At low delta K, the plastic zone diameter is smaller than the subgrain size and FCP progresses along (100) planes due to either local lattice decohesion or aluminum-lithium hydride cracking. For inert environments (vacuum, helium, and oxygen), or at high delta K where the hydrogen effect on da/dN is small, FCP is along (111) slip planes; this mode does not transition with increasing delta K and plastic zone size. The SGC and (100) crystallographic cracking modes, and the governing influence of the crack tip process zone volume (delta K), support hydrogen embrittlement rather than a surface film rupture and anodic dissolution mechanism for environmental FCP. Multi-sloped log da/dN-log delta K behavior is produced by changes in process zone hydrogen-microstructure interactions, and not by purely micromechanical-microstructure interactions, in contradiction to microstructural distance-based fatigue models.

  11. Process Optimization of Dual-Laser Beam Welding of Advanced Al-Li Alloys Through Hot Cracking Susceptibility Modeling

    Science.gov (United States)

    Tian, Yingtao; Robson, Joseph D.; Riekehr, Stefan; Kashaev, Nikolai; Wang, Li; Lowe, Tristan; Karanika, Alexandra

    2016-07-01

    Laser welding of advanced Al-Li alloys has been developed to meet the increasing demand for light-weight and high-strength aerospace structures. However, welding of high-strength Al-Li alloys can be problematic due to the tendency for hot cracking. Finding suitable welding parameters and filler material for this combination currently requires extensive and costly trial and error experimentation. The present work describes a novel coupled model to predict hot crack susceptibility (HCS) in Al-Li welds. Such a model can be used to shortcut the weld development process. The coupled model combines finite element process simulation with a two-level HCS model. The finite element process model predicts thermal field data for the subsequent HCS hot cracking prediction. The model can be used to predict the influences of filler wire composition and welding parameters on HCS. The modeling results have been validated by comparing predictions with results from fully instrumented laser welds performed under a range of process parameters and analyzed using high-resolution X-ray tomography to identify weld defects. It is shown that the model is capable of accurately predicting the thermal field around the weld and the trend of HCS as a function of process parameters.

  12. Corrosion behavior of 2195 and 1420 Al-Li alloys in neutral 3.5% NaCl solution under tensile stress

    Institute of Scientific and Technical Information of China (English)

    LI Jin-feng; CHEN Wen-jing; ZHAO Xu-shan; REN Wen-da; ZHENG Zi-qiao

    2006-01-01

    The corrosion behaviors of 1420 and 2195 Al-Li alloys under 308 and 490 MPa tensile stress respectively in neutral 3.5% NaCl solution were investigated using electrochemical impedance spectroscopy(EIS) and scanning electron microscope(SEM). It is found that the unstressed 1420 alloy is featured with large and discrete pits, while general corrosion and localized corrosion including intergranular corrosion and pitting corrosion occur on the unstressed 2195 alloy. As stress is applied to 1420 alloy, the pit becomes denser and its size is decreased. While, for the stressed 2195 alloy, intergranular corrosion is greatly aggravated and severe general corrosion is developed from connected pits. The EIS analysis shows that more severe general corrosion and localized corrosion occur on the stressed 2195 Al-Li alloy than on 1420 Al-Li alloy. It is suggested that tensile stress has greater effect on the corrosion of 2195 Al-Li alloy than on 1420 Al-Li alloy.

  13. Influence of the Local Chemical Composition on the Mechanical Properties of Laser Beam Welded Al-Li Alloys

    Science.gov (United States)

    Enz, Josephin; Riekehr, Stefan; Ventzke, Volker; Kashaev, Nikolai

    The increasing interest of the aircraft industry in reduction of structural weight of aircrafts has resulted in the development of lightweight and high-strength Al-Li alloys as well as in the introduction of laser beam welding to the manufacturing process. The objective of this study is the investigation of the influence of variations in the chemical composition on local mechanical properties, like micro-hardness and micro-tensile strength, of CO 2 laser beam welded skin-stringer joints made from AA2196 and AA2198. Additionally the influence of the welding process on weld chemistry is studied in view of the improvement of the weld quality.

  14. Microstructural characterization of an Al-li-mg-cu alloy by correlative electron tomography and atom probe tomography.

    Science.gov (United States)

    Xiong, Xiangyuan; Weyland, Matthew

    2014-08-01

    Correlative electron tomography and atom probe tomography have been carried out successfully on the same region of a commercial 8090 aluminum alloy (Al-Li-Mg-Cu). The combination of the two techniques allows accurate geometric reconstruction of the atom probe tomography data verified by crystallographic information retrieved from the reconstruction. Quantitative analysis of the precipitate phase compositions and volume fractions of each phase have been obtained from the atom probe tomography and electron tomography at various scales, showing strong agreement between both techniques.

  15. Liquid oxygen LOX compatibility evaluations of aluminum lithium (Al-Li) alloys: Investigation of the Alcoa 2090 and MMC weldalite 049 alloys

    Science.gov (United States)

    Diwan, Ravinder M.

    1989-01-01

    The behavior of liquid oxygen (LOX) compatibility of aluminum lithium (Al-Li) alloys is investigated. Alloy systems of Alcoa 2090, vintages 1 to 3, and of Martin Marietta Corporation (MMC) Weldalite 049 were evaluated for their behavior related to the LOX compatibility employing liquid oxygen impact test conditions under ambient pressures and up to 1000 psi. The developments of these aluminum lithium alloys are of critical and significant interest because of their lower densities and higher specific strengths and improved mechanical properties at cryogenic temperatures. Of the different LOX impact tests carried out at the Marshall Space Flight Center (MSFC), it is seen that in certain test conditions at higher pressures, not all Al-Li alloys are LOX compatible. In case of any reactivity, it appears that lithium makes the material more sensitive at grain boundaries due to microstructural inhomogeneities and associated precipitate free zones (PFZ). The objectives were to identify and rationalize the microstructural mechanisms that could be relaxed to LOX compatibility behavior of the alloy system in consideration. The LOX compatibility behavior of Al-Li 2090 and Weldalite 049 is analyzed in detail using microstructural characterization techniques with light optical metallography, scanning electron microscopy (SEM), electron microprobe analysis, and surface studies using secondary ion mass spectrometry (SIMS), electron spectroscopy in chemical analysis (ESCA) and Auger electron spectroscopy (AES). Differences in the behavior of these aluminum lithium alloys are assessed and related to their chemistry, heat treatment conditions, and microstructural effects.

  16. Structural properties and relative stability of (meta)stable ordered, partially ordered, and disordered Al-Li alloy phases

    Science.gov (United States)

    Alam, Aftab; Johnson, D. D.

    2012-04-01

    We resolve issues that have plagued reliable prediction of relative phase stability for solid solutions and compounds. Due to its commercially important phase diagram, we showcase the Al-Li system because historically density-functional theory (DFT) results show large scatter and limited success in predicting the structural properties and stability of solid solutions relative to ordered compounds. Using recent advances in an optimal basis-set representation of the topology of electronic charge density (and, hence, atomic size), we present DFT results that agree reasonably well with all known experimental data for the structural properties and formation energies of ordered, off-stoichiometric partially ordered, and disordered alloys, opening the way for reliable study in complex alloys.

  17. Study on electrochemical preparation of Al-Li-Y alloys from Y2O3 in LiCl-KCl-AlCl3 molten salts

    Institute of Scientific and Technical Information of China (English)

    LI Yaming; WANG Fengli; ZHANG Milin; HAN Wei; TIAN Yang

    2011-01-01

    The electrochemical preparaton of Al-Li-Y alloys from LiCl-KCl-A1Cl3-Y2O3 system was studied. The chlorination of Y2O3 by AlCl3 led to the formation of Y (Ⅲ) ions in the molten salts. Cyclic voltammogram (CV) showed that the underpotential deposition (UPD) of yttrium on pre-deposited aluminum caused the formation of Al-Y alloy. Al-Li-Y alloys with different yttriurn contents were obtained by galvanostatic electrolysis and analysed by SEM-EDS and ICP. The ICP results showed that the lithium and yttrium contents in Al-Li-Y alloysdepended on the addition of AlCl3 into the melts.

  18. Cladding Alloys for Fluoride Salt Compatibility

    Energy Technology Data Exchange (ETDEWEB)

    Muralidharan, Govindarajan [ORNL; Wilson, Dane F [ORNL; Walker, Larry R [ORNL; Santella, Michael L [ORNL; Holcomb, David Eugene [ORNL

    2011-06-01

    This report provides an overview of several candidate technologies for cladding nickel-based corrosion protection layers onto high-temperature structural alloys. The report also provides a brief overview of the welding and weld performance issues associated with joining nickel-clad nickel-based alloys. From the available techniques, two cladding technologies were selected for initial evaluation. The first technique is a line-of-sight method that would be useful for cladding large structures such as vessel interiors or large piping. The line-of-sight method is a laser-based surface cladding technique in which a high-purity nickel powder mixed into a polymer binder is first sprayed onto the surface, baked, and then rapidly melted using a high-power laser. The second technique is a vapor phase technique based on the nickel-carbonyl process that is suitable for cladding inaccessible surfaces such as the interior surfaces of heat exchangers. An initial evaluation for performed on the quality of nickel claddings processed using the two selected cladding techniques.

  19. The effect of zinc additions on the environmental stability of Alloy 8090 (Al-Li-Cu-Mg-Zr)

    Science.gov (United States)

    Kilmer, Raymond J.; Stoner, G. E.

    1991-01-01

    Stress corrosion cracking (SCC) remains a problem in both Al-Li and conventional Al heat treatable alloys. It has recently been found that relatively small additions (less than or approximately 1 wt-percent) of Zn can dramatically improve the SCC performance of alloy 8090 (Al-Li-Cu-Mg-Zr). Constant load time to failure experiments using cylindrical tensile samples loaded between 30 and 85 percent of TYS indicate improvements of orders of magnitude over the baseline 8090 for the Zn-containing alloys under certain aging conditions. However, the toughnesses of the alloys were noticeably degraded due to the formation of second phase particles which primarily reside on grain and subgrain boundaries. EDS revealed that these intermetallic particles were Cu and Zn rich. The particles were present in the T3 condition and were not found to be the result of quench rate, though their size and distribution were. At 5 hours at 160 C, the alloys displayed the greatest susceptibility to SCC but by 20 hours at 160 C the alloys demonstrated markedly improved TTF lifetimes. Aging past this time did not provide separable TTF results, however, the alloy toughnesses continued to worsen. Initial examination of the alloys microstructures at 5 and 20 hours indicated some changes most notably the S' and delta' distributions. A possible model by which this may occur will be explored. Polarization experiments indicated a change in the trend of E(sub BR) and passive current density at peak aging as compared to the baseline 8090. Initial pitting experiments indicated that the primary pitting mechanism in chloride environments is one occurring at constituent (Al-Fe-Cu) particles and that the Cu and Zn rich boundary precipitates posses a breakaway potential similar to that of the matrix acting neither anodic or cathodic in the first set of aerated 3.5 w/o NaCl experiments. Future work will focus on the identification of the second phase particles, evaluation of K(sub 1SCC) and plateau da/dt via

  20. Electrochemical behaviour and codeposition of Al-Li-Er alloys in LiCl-KCl-AlCl3-Er2O3 melts

    Institute of Scientific and Technical Information of China (English)

    SUN Yi; ZHANG Milin; HAN Wei; YAN Yongde; YANG Yusheng; SUN Yunxia

    2013-01-01

    The electrochemical behaviour of Al,Li,and Er were investigated by electrochemical techniques,such as cyclic voltammograms,chronopotentiometric,chronoamperograms,and open circuit chronopotentiogram on molybdenum electrodes.The results showed that the underpotential deposition of erbium on pre-deposited A1 electrodes formed two A1-Er intermetallic compounds.The codeposition of Al,Li,Er occurred and formed Al-Li-Er alloys in LiCl-KCl-AlCl3-Er2O3 melts at 773 K.Different phases such as Al2Er,Al2Er3 and βLi phase of Al-Li-Er alloys were prepared by galvanostatic electrolysis and characterized by X-ray diffraction (XRD).Scanning electron microscopy (SEM) indicated that Er element mainly distributed at the grain boundary.ICP analyses showed that lithium and erbium contents of Al-Li-Er alloys could be controlled by AlCl3 and Er2O3 concentration and electrochemical parameters.

  1. Effect of Rare Earth Cerium on Yield Strength Anisotropy of Al-Li Alloy Sheet and Its Theoretical Prediction

    Institute of Scientific and Technical Information of China (English)

    赵志龙; 刘林; 陈铮

    2004-01-01

    The variation of yield strength along rolling direction, transverse direction and 45° to transverse direction of 2090 Al-Li alloy and 2090+Ce alloy sheet containing rare earth cerium was comparatively investigated. The difference of deformation texture in these two alloy sheets was analyzed by means of X-ray orientation distribution function (ODF). The results show that cerium has the effects of enhancing the Brass and S rolling texture components and reducing the recrystallized texture components of Cube and Goss. This is the reason that the anisotropic degree of yield strength in 2090+Ce sheet is higher than that of 2090 alloy sheet. The prediction of yield strength along various orientations in two alloy sheets was done based on Taylor/Bishop-Hill model, and the strengthening effect of grain boundary was evaluated using Hall-Petch relationship. A modified plastic inclusion model was proposed using the concept of grain-orientation factor and T1 phase orientation factor by fitting with tensile test results.

  2. Characterization of the precipitates in Al-Li(8090) alloy using thermal measurements and TEM examinations

    Science.gov (United States)

    Gaber, A.; Afify, N.

    2002-04-01

    Variation of thermophysical properties of Al-Li (8090) quenched from the solid solution state (803 K) during heating (10 K/min) has been used to determine the temperatures at which the phase transformations take place. Transmission electron microscopic examinations were used to characterize the developed precipitates. It has been shown that the thermal properties can be used as a powerful tool for detecting phase transformations. Microstructural examinations after aging at 373, 438, 563 and 673 K revealed the formation of GP zones, δ‧-(Al 3Li), T B-(Al 7Cu 4Li) and T 2-(Al 6CuLi 3) precipitates, respectively. δ‧-particles and T B-(Al 7Cu 4Li) were observed to be nucleated intragranularly, whereas T 2-particles were observed to grow on the grain boundaries.

  3. Computer simulation of Al-Li alloy retrogression%Al-Li合金回归过程的数值模拟

    Institute of Scientific and Technical Information of China (English)

    徐国栋; 沈智

    2012-01-01

    基于离散格点形式的Langevin方程,以Al-12%Li合金为对象,模拟合金完全回归的过程。结果表明,Al-Li合金完全回归过程经过Li的固溶,δ'相的回归,δ'相的无序化;Al-Li合金完全回归,其温度需要达到一定条件才可以发生,否则即使延长回归时间,有序相也只发生部分回归;温度越高,Al-Li合金完全回归时间越短,Li含量越低,发生完全回归的温度越低。%Based on Langevin equation of the discrete format,the evolution of retrogression of Al-12%Li alloy is investigated using computer simulation.The results show that the complete retrogression process of Al-Li alloy as solution of lithium,retrogression of δ′ and disorder of δ′.Al-Li alloy could retrogress completely when the temperature was reached certain conditions,otherwise even prolonged heat treatment time,the ordered phase could partially retrogress.The higher the temperature,the shorter time of Al-Li alloy completely retrogress.The less Li content,the lower temperature of Al-Li alloy completely retrogress.

  4. Study on the characteristics and thermal stability of nanostructures in adiabatic shear band of 2195 Al-Li alloy

    Science.gov (United States)

    Yang, Yang; Chen, Yadong; Jiang, Lihong; Li, Meng; Zhang, Qingming; Tang, Tiegang

    2015-11-01

    Adiabatic shear bands (ASB) were obtained by dynamic shearing with a split Hopkinson pressure bar in the hat-shaped specimens of 2195-T6 Al-Li alloy. TEM observations reveal that grains in ASB are mainly equiaxed with the grain size from 50 to 100 nm. The kinetics possibility of instant refinement of grains can well be explained with the rotation dynamic recrystallization mechanism. EBSD is used to investigate microstructure evolution in ASB after annealed at 100-400 °C for 1 h. Results show that grain size increases rapidly at higher annealing temperature, and grains grow from 0.22 μm at 300 °C to 1.77 μm at 400 °C. Microhardness measurement indicated that the microhardness value rises slowly with temperature increases and then drops quickly at 300 °C. The study indicates that the nanostructure in ASB is thermally stable below 300 °C.

  5. Electrochemical Formation of Al-Li Alloys by Codeposition of Al and Li from LiCl-KCl-AlF3 Melts at 853 K

    Institute of Scientific and Technical Information of China (English)

    SUN Yi; ZHANG Mi-lin; HAN Wei; LI Mei; YANG Yu-sheng

    2013-01-01

    The electrochemical behavior of Al(Ⅲ) ions was studied in molten LiCl-KCl melts on a molybdenum electrode.Cyclic voltammetry,chronopotentiometry and chronoamperometry were used to explore the deposition mechanism of Al and Li.Cyclic voltammetry expriment indicates that under potential deposition(UPD) of lithium on pre-deposited aluminium led to the formation of liquid Al-Li alloys at 853 K.The diffusion coefficient of Al(Ⅲ) ions at 853 K in LiCl-KCl-AlF3(1%,mass fraction) melts was determined to be (2.79±0.05)× 10-5 cm2/s.Chronopotentiograms and chronoamperograms demonstrate that the codeposition of Al(Ⅲ) and Li(Ⅰ) ions formed Al-Li alloys at cathodic current densities higher than-0.28 A/cm2 or cathodic potentials more negative than-2.20 V.X-Ray diffraction(XRD) pattern indicates that Al-Li alloys with different phases formed via galvanostatic electrolysis.Inductively coupled plasma(ICP) analyses of the samples obtained by electrolysis show that lithium and aluminium contents of Al-Li alloys could be controlled by AlF3 concentration and current intensity.

  6. Three-dimensional effects of microstructures on short fatigue crack growth in an Al-Li 8090 alloy

    Science.gov (United States)

    Wen, Wei; Zhai, Tongguang

    2011-09-01

    Al-Li 8090 alloy specimens were fatigued using a self-aligning four-point bend rig at R = 0.1 and room temperature, in air, under constant maximum stress control. The crystallographic characteristics of fatigue crack initiation and early growth were studied using EBSD. It was found that the growth behaviour of a short crack were controlled by the twist (α) and tilt (β) components of crack plane deflection across each of the first 20 grain boundaries along the crack path, and that the α angle at the first grain boundary encountered by a micro-crack was critical in determining whether the crack could become propagating or non-propagating. In addition to the orientations of the two neighbouring grains, the tilt of their boundary could also affect α across the boundary. A minimum α-map for a vertical micro-crack was calculated to evaluate the resistance to crack growth into a neighbouring grain with a random orientation. Such an α-map is of value in alloy design against fatigue damage by optimising texture components in the alloys.

  7. Environmental fatigue of an Al-Li-Cu alloy. Part 3: Modeling of crack tip hydrogen damage

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1992-01-01

    Environmental fatigue crack propagation rates and microscopic damage modes in Al-Li-Cu alloy 2090 (Parts 1 and 2) are described by a crack tip process zone model based on hydrogen embrittlement. Da/dN sub ENV equates to discontinuous crack advance over a distance, delta a, determined by dislocation transport of dissolved hydrogen at plastic strains above a critical value; and to the number of load cycles, delta N, required to hydrogenate process zone trap sites that fracture according to a local hydrogen concentration-tensile stress criterion. Transgranular (100) cracking occurs for process zones smaller than the subgrain size, and due to lattice decohesion or hydride formation. Intersubgranular cracking dominates when the process zone encompasses one or more subgrains so that dislocation transport provides hydrogen to strong boundary trapping sites. Multi-sloped log da/dN-log delta K behavior is produced by process zone plastic strain-hydrogen-microstructure interactions, and is determined by the DK dependent rates and proportions of each parallel cracking mode. Absolute values of the exponents and the preexponential coefficients are not predictable; however, fractographic measurements theta sub i coupled with fatigue crack propagation data for alloy 2090 established that the process zone model correctly describes fatigue crack propagation kinetics. Crack surface films hinder hydrogen uptake and reduce da/dN and alter the proportions of each fatigue crack propagation mode.

  8. Effect of thermal processing practices on the properties of superplastic Al-Li alloys

    Science.gov (United States)

    Hales, Stephen J.; Lippard, Henry E.

    1993-01-01

    The effect of thermal processing on the mechanical properties of superplastically formed structural components fabricated from three aluminum-lithium alloys was evaluated. The starting materials consisted of 8090, 2090, and X2095 (Weldalite(TM) 049), in the form of commercial-grade superplastic sheet. The experimental test matrix was designed to assess the impact on mechanical properties of eliminating solution heat treatment and/or cold water quenching from post-forming thermal processing. The extensive hardness and tensile property data compiled are presented as a function of aging temperature, superplastic strain and temper/quench rate for each alloy. The tensile properties of the materials following superplastic forming in two T5-type tempers are compared with the baseline T6 temper. The implications for simplifying thermal processing without degradation in properties are discussed on the basis of the results.

  9. Cryogenic Treatment of Al-Li Alloys for Improved Weldability, Repairability, and Reduction of Residual Stresses

    Science.gov (United States)

    Malone, Tina W.; Graham, Benny F.; Gentz, Steven J. (Technical Monitor)

    2001-01-01

    Service performance has shown that cryogenic treatment of some metals provides improved strength, fatigue life, and wear resistance to the processed material. Effects such as these were initially discovered by NASA engineers while evaluating spacecraft that had returned from the cold vacuum of space. Factors such as high cost, poor repairability, and poor machinability are currently prohibitive for wide range use of some aerospace aluminum alloys. Application of a cryogenic treatment process to these alloys is expected provide improvements in weldability and weld properties coupled with a reduction in repairs resulting in a significant reduction in the cost to manufacture and life cycle cost of aerospace hardware. The primary purpose of this effort was to evaluate the effects of deep cryogenic treatment of some aluminum alloy plate products, welds, and weld repairs, and optimize a process for the treatment of these materials. The optimized process is being evaluated for improvements in properties of plate and welds, improvements in weldability and repairability of treated materials, and as an alternative technique for the reduction of residual stresses in repaired welds. This paper will present the results of testing and evaluation conducted in this effort. These results will include assessments of changes in strength, toughness, stress corrosion susceptability, weldability, repairability, and reduction in residual stresses of repaired welds.

  10. Interactions between drops of molten Al-Li alloys and liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Hyder, M.L. [Westinghouse Savannah River Co., Aiken, SC (United States); Nelson, L.S. [Sandia National Labs., Albuquerque, NM (United States); Duda, P.M.; Hyndman, D.A. [Ktech Corp., Albuquerque, NM (United States)

    1993-08-01

    Sandia National Laboratories, at the request of the Savannah River Technology Center (SRTC), studied the interactions between single drops of molten aluminum-lithium alloys and water. Most experiments were performed with ``B`` alloy (3.1 w/o Li, balance A1). Objectives were to develop experimental procedures for preparing and delivering the melt drops and diagnostics for characterizing the interactions, measure hydrogen generated by the reaction between melt and water, examine debris recovered after the interaction, determine changes in the aqueous phase produced by the melt-water chemical reactions, and determine whether steam explosions occur spontaneously under the conditions studied. Although many H{sub 2} bubbles were generated after the drops entered the water, spontaneous steam explosions never occurred when globules of the ``B`` alloy at temperatures between 700 and 1000C fell freely through water at room temperature, or upon or during subsequent contact with submerged aluminum or stainless steel surfaces. Total amounts of H{sub 2} (STP) increased from about 2 to 9 cm{sup 3}/per gram of melt as initial melt temperature increased over this range of temperatures.

  11. Prediction of forming limit curve (FLC) for Al-Li alloy 2198-T3 sheet using different yield functions

    Institute of Scientific and Technical Information of China (English)

    Li Xiaoqiang; Song Nan; Guo Guiqiang; Sun Zhonggang

    2013-01-01

    The Forming Limit Curve (FLC) of the third generation aluminum-lithium (Al-Li) alloy 2198-T3 is measured by conducting a hemispherical dome test with specimens of different widths. The theoretical prediction of the FLC of 2198-T3 is based on the M-K theory utilizing respectively the von Mises, Hill’48, Hosford and Barlat 89 yield functions, and the different predicted curves due to different yield functions are compared with the experimentally measured FLC of 2198-T3. The results show that though there are differences among the four predicted curves, yet they all agree well with the experimentally measured curve. In the area near the planar strain state, the predicted curves and experimentally measured curve are very close. The predicted curve based on the Hosford yield function is more accurate under the tension-compression strain states described in the left part of the FLC, while the accuracy is better for the predicted curve based on Hill’48 yield function under the tension-tension strain states shown in the right part.

  12. Texture Evolution within the Thermomechanically Affected Zone of an Al-Li Alloy 2195 Friction Stir Weld

    Science.gov (United States)

    Tayon, Wesley A.; Domack, Marcia S.; Hoffman, Eric K.; Hales, Stephen J.

    2013-11-01

    Friction stir welding (FSW) of Al -Li alloy 2195 plate produces strong texture gradients. The microstructural characteristics evolve from the base plate, through the thermomechanically affected zone (TMAZ), to the weld nugget interface. In the current study, electron backscattered diffraction (EBSD) analyses were employed to quantify the spatial distribution of texture gradients associated with the evolution of texture within the TMAZ. The strong texture of the base plate enabled the texture evolution to be characterized as a function of location. Systematic partitioning of EBSD data relative to the degree of lattice rotation at each point accurately captured the crystallographic transitions across the advancing side TMAZ. Over a large section of this region, the texture evolves as a result of continuous rigid body rotations. The rigid body rotations were correlated with the complex material flow patterns commonly associated with the FSW process and prior observations of shear-related textures. Finally, a correlation between texture and fracture in a subscale tensile specimen is observed, where failure occurs within a visible band of low-Taylor factor grains.

  13. Temperature effects on the deformation and fracture of Al-Li-Cu-In alloys

    Science.gov (United States)

    Wagner, John A.; Gangloff, Richard P.

    1991-01-01

    The crack initiation and growth fracture resistance of Al-Cu-Li and Al-Cu-Li-In alloys were characterized and optimized for cryogenic tank applications. Presently, the effects of stress state and temperature is being determined on the fracture toughness and fracture mechanisms of commercially available Vintage 3 2090-T81 and experimental 2090+In-T6. Precracked J-integral specimens of both alloys were tested at ambient and cryogenic temperatures in the plane stress and plane strain conditions. Considering ambient temperature, results showed that 2090-T81 exhibited the highest toughness in both plane strain and plane stress conditions. For the plane strain condition, reasonable crack initiation and growth toughness of 1090-T81 are associated with a significant amount of delamination and transgranular fracture. Plane stress toughnesses were higher and fracture was characterized by shear cracking with minimal delaminations. In comparisons, the fracture behavior of 2090+In-T6 is significantly degraded by subgrain boundary precipitation. Toughness is low and characterized by intersubgranular fracture with no delamination in the plane stress or plane strain conditions. Intersubgranular cracking is a low energy event which presumably occurs prior to the onset of slip band cracking. Copious grain boundary precipitation is atypical of commercially available 2090. At cryogenic temperatures, both alloys exhibit increased yield strength, toughness, and amount of delamination and shear cracking. The change in fracture mode of 2090+In-T6 from intersubgranular cracking at ambient temperature to a combination of intersubgranular cracking, shear cracking, and delamination at cryogenic temperature is the subject of further investigation.

  14. Disorder in Al-li-cu and Al-mn-si icosahedral alloys.

    Science.gov (United States)

    Heiney, P A; Bancel, P A; Horn, P M; Jordan, J L; Laplaca, S; Angilello, J; Gayle, F W

    1987-10-30

    Faceted dendrites of icosahedral AL(6)Li(3)Cu have been studied by high-resolution x-ray scattering. The samples display long-range icosahedral symmetry both in their diffraction patterns and in their macroscopic morphology. Despite the appearance of well-defined facets, the samples have a high degree of atomic disorder. The Bragg peaks have symmetry-dependent shapes and widths that scale linearly with G perpendicular (phason momentum). The peak widths are surprisingly similar to those found in icosahedral Al-Mn-Si alloys in both their absolute magnitude and their dependence on G perpendicular. The origin of these features in models for the icosahedral phase is discussed.

  15. B218 Weld Filler Wire Characterization for Al-Li Alloy 2195

    Science.gov (United States)

    Bjorkman, Gerry; Russell, Carolyn

    2000-01-01

    NASA Marshall Space Flight Center, Lockheed Martin Space Systems- Michoud Operations, and McCook Metals have developed an aluminum-copper weld filler wire for fusion welding aluminum lithium alloy 2195. The aluminum-copper based weld filler wire has been identified as B218, a McCook Metals designation. B218 is the result of six years of weld filler wire development funded by NASA, Lockheed Martin, and McCook Metals. The filler wire chemistry was developed to produce enhanced 2195 weld and repair weld mechanical properties over the 4043 aluminum-silicon weld filler wire, which is currently used to weld 2195 on the Super Lightweight External Tank for the NASA Space Shuttle Program. An initial characterization was performed consisting of a repair weld evaluation using B218 and 4043 weld filler wires. The testing involved room temperature and cryogenic repair weld tensile testing along with fracture toughness testing. From the testing, B218 weld filler wire produce enhanced repair weld tensile strength, ductility, and fracture properties over 4043. B218 weld filler wire has proved to be a superior weld filler wire for welding aluminum lithium alloy 2195 over 4043.

  16. Superplastic forming of Al-Li alloys for lightweight, low-cost structures

    Science.gov (United States)

    Hales, Stephen J.; Wagner, John A.

    1991-01-01

    Superplastic forming of advanced aluminum alloys is being evaluated as an approach for fabricating low-cost, light-weight, cryogenic propellant tanks. Built-up structure concepts (with inherent reduced scrap rate) are under investigation to offset the additional raw material expenses incurred by using aluminum lithium alloys. This approach to fabrication offers the potential for significant improvements in both structural efficiency and overall manufacturing costs. Superplasticity is the ability of specially processed material to sustain very large forming strains without failure at elevated temperatures under controlled deformation conditions. It was demonstrated that superplastic forming technology can be used to fabricate complex structural components in a single operation and increase structural efficiency by as much as 60 percent compared to conventional configurations in skin-stiffened structures. Details involved in the application of this technology to commercial grade superplastic aluminum lithium material are presented. Included are identification of optimum forming parameters, development of forming procedures, and assessment of final part quality in terms of cavitation volume and thickness variation.

  17. Environmental fatigue of an Al-Li-Cu alloy. I - Intrinsic crack propagation kinetics in hydrogenous environments

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1991-01-01

    Deleterious environmental effects on steady-state, intrinsic fatigue crack propagation (FCP) rates (da/dN) in peak aged Al-Li-Cu alloy 2090 are established by electrical potential monitoring of short cracks with programmed constant delta K and K(sub max) loading. The da/dN are equally unaffected by vacuum, purified helium, and oxygen but are accelerated in order of decreasing effectiveness of aqueous 1 percent NaCl with anodic polarization, pure water vapor, moist air, and NaCl with cathodic polarization. While da/dN depends on delta K(sup 4.0) for the inert gases, water vapor and chloride induced multiple power-laws, and a transition growth rate 'plateau'. Environmental effects are strongest at low delta K. Crack tip damage is ascribed to hydrogen embrittlement because of the following: (1) accelerated da/dN due to part-per-million levels of H2O without condensation; (2) impeded molecular flow model predictions of the measured water vapor pressure dependence of da/dN as affected by mean crack opening; (3) the lack of an effect of film-forming O2; (4) the likelihood for crack tip hydrogen production in NaCl; and (5) the environmental and delta K-process zone volume dependencies of the microscopic cracking modes. For NaCl, growth rates decrease with decreasing loading frequency, with the addition of passivating Li2CO3, and upon cathodic polarization. These variables increase crack surface film stability to reduce hydrogen entry efficiency. The hydrogen environmental FCP resistance of 2090 is similar to other 2000 series alloys and is better than 7075.

  18. Environmental fatigue of an Al-Li-Cu alloy. Part 1: Intrinsic crack propagation kinetics in hydrogenous environments

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1991-01-01

    Deleterious environmental effects on steady-state, intrinsic fatigue crack propagation (FCP) rates (da/dN) in peak aged Al-Li-Cu alloy 2090 are established by electrical potential monitoring of short cracks with programmed constant delta K and K(sub max) loading. The da/dN are equally unaffected by vacuum, purified helium, and oxygen but are accelerated in order of decreasing effectiveness by aqueous 1 percent NaCl with anodic polarization, pure water vapor, moist air, and NaCl with cathodic polarization. While da/dN depends on delta K(sup 4.0) for the inert gases, water vapor and chloride induced multiple power-laws, and a transition growth rate 'plateau'. Environmental effects are strongest at low delta K. Crack tip damage is ascribed to hydrogen embrittlement because of the following: (1) accelerated da/dN due to part-per-million levels of H2O without condensation; (2) impeded molecular flow model predictions of the measured water vapor pressure dependence of da/dN as affected by mean crack opening; (3) the lack of an effect of film-forming O2; (4) the likelihood for crack tip hydrogen production in NaCl, and (5) the environmental and delta K-process zone volume dependencies of the microscopic cracking modes. For NaCl, growth rates decrease with decreasing loading frequency, with the addition of passivating Li2CO3, and upon cathodic polarization. These variables increase crack surface film stability to reduce hydrogen entry efficiency. The hydrogen environmental FCP resistance of 2090 is similar to other 2000 series alloys and is better than 7075.

  19. Computer simulation of interface evolution for an Al-Li alloy during early aging stage

    Institute of Scientific and Technical Information of China (English)

    TANG Liying; WANG Yongxin; CHEN Zheng; LU Yanli; ZHANG Jianjun

    2004-01-01

    The nucleation of ordered phase was simulated based on microscopic diffusion equation and the assumptions of the classical nucleation theory were examined. The quantitative calculations of interface thickness evolution were accomplished for the first time. It was found that the interfaces between ordered phase and disordered matrix were diffuse. The interface thickness decreased with time, from the initial 1.2 nm to an equilibrium value 0.6 nm. The ratios of the radius of ordered particles and the interface thickness monotonously increased, but they were of the same order of magnitude all the time. The sharp interface assumption should not be adopted in this stage. For the Al-10%Li (atom fraction) alloy aged at 192℃, the assumptions of the classical nucleation theory disagreed with the facts. The phase transformation followed the non-classical nucleation mechanism and the applicable scope of the classical nucleation should be confined.

  20. Recent Advances in Near-Net-Shape Fabrication of Al-Li Alloy 2195 for Launch Vehicles

    Science.gov (United States)

    Wagner, John; Domack, Marcia; Hoffman, Eric

    2007-01-01

    Recent applications in launch vehicles use 2195 processed to Super Lightweight Tank specifications. Potential benefits exist by tailoring heat treatment and other processing parameters to the application. Assess the potential benefits and advocate application of Al-Li near-net-shape technologies for other launch vehicle structural components. Work with manufacturing and material producers to optimize Al-Li ingot shape and size for enhanced near-net-shape processing. Examine time dependent properties of 2195 critical for reusable applications.

  1. Design of multistep aging treatments of 2099 (C458) Al-Li alloy

    Science.gov (United States)

    Romios, M.; Tiraschi, R.; Ogren, J. R.; Es-Said, O. S.; Parrish, C.; Babel, H. W.

    2005-10-01

    Multistep artificial aging treatments coupled with various natural aging times for aluminum lithium 2099 alloy (previously called C458) are discussed to obtain mechanical tensile properties in the T6 condition that match those in the T861 condition, having a yield strength in the range of 414-490 MPa (60-71 ksi), an ultimate strength in the range of 496-538 MPa (72-78 ksi), and 10-13% elongation. Yield and ultimate tensile strengths from 90-100% of the strength of the as-received material (in the T861 condition) were obtained. The highest tensile strengths were consistently obtained with two-step, low-to-high temperature artificial aging treatments consisting of a first step at 120 °C (248 °F) for 12-24 h followed by a second step between 165 and 180 °C (329-356 °F) for 48-100 h. These T6-type heat treatments produced average yield and ultimate strengths in the longitudinal direction in the range of 428-472 MPa (62.1-68.5 ksi) and 487-523 MPa (70.6-75.9 ksi), respectively, as well as lower yield strength anisotropy when compared with the as-received material in the T861 condition.

  2. The solubility of hydrogen in liquid binary Al-Li alloys

    Science.gov (United States)

    Anyalebechi, P. N.; Talbot, D. E. J.; Granger, D. A.

    1988-04-01

    The solubility of hydrogen in liquid binary aluminum alloys with 1, 2, and 3 wt pct lithium has been determined for the temperature range of 913 to 1073 K and pressure 5.3 × 104 to 10.7 × 104 Pa, using an appropriate version of Sieverts’ method. The results fit the Van’t Hoff isobar and Sieverts’ isotherm and the solubility, S, is given by: Al-1 pct Li: log( S/S°) - 1/2 log( P/P°) = -2113/T/k + 2.568 Al-1 pct Li: log( S/S°) - 1/2 log( P/P°) = -2797/T/k + 3.329 Al-1 pct Li: log( S/S°) - 1/2 log( P/P°) = -2889/T/k + 3.508 where S° is a standard value of solubility equal to 1 cm3 of diatomic hydrogen measured at 273 K and 101,325 Pa per 100 g of metal, and P° is a standard pressure equal to 101,325 Pa. Added lithium progressively increases the solubility of hydrogen in liquid aluminum, due more to its effect on the entropy of solution of hydrogen, through its influence on the liquid metal structure than to an increase in the solute hydrogen atom binding enthalpy.

  3. Laser-induced reversion of $\\delta^{'}$ precipitates in an Al-Li alloy: Study on temperature rise in pulsed laser atom probe

    CERN Document Server

    Khushaim, Muna; Al-Kassab, Talaat

    2015-01-01

    The influence of tuning the laser energy during the analyses on the resulting microstructure in a specimen utilizing an ultra-fast laser assisted atom probe was demonstrated by a case study of a binary Al-Li alloy. The decomposition parameters, such as the size, number density, volume fraction and composition of $\\delta^{'}$ precipitates, were carefully monitored after each analysis. A simple model was employed to estimate the corresponding specimen temperature for each value of the laser energy. The results indicated that the corresponding temperatures for the laser energy in the range of 10 to 80 pJ are located inside the miscibility gap of the binary Al-Li phase diagram and fall into the metastable equilibrium field. In addition, the corresponding temperature for a laser energy of 100 pJ was in fairly good agreement with reported range of $\\delta^{'}$ solvus temperature, suggesting a result of reversion upon heating due to laser pulsing.

  4. Ferrous Alloy Powder for Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    WEN Jialing; NIU Quanfeng; XU Yanmin

    2005-01-01

    This investigation aimed at how to improve the hardness and wear resistance by B, Si and Cr, and how to improve the synthesis property by Re (rare-earth element). Based on the experiment of Fe-based alloys of Fe-Cr-Ni-B-Si-Re, through experiments and a serious of synthesis analysis, including surface quality, spectrum composite, micro-hardness, scanning electron microscopy, as well as the synthesis evaluation,etc, prescriptions were optimized. As a result, a Fe-Cr-Ni-B-Si-Re cladding material with a high property was obtained.

  5. Evaluation of Engineering Properties of AL-Li Alloy X2096-T8A3 Extrusion Products

    Science.gov (United States)

    Flom, Y.; Viens, M.; Wang, L.

    1999-01-01

    Mechanical, thermal fatigue and stress corrosion properties were determined for the two lots of Al-Li X2096-T8A3 extruded beams. Based on the test results, the beams were accepted as the construction material for fabrication of the Hubble Space Telescope new Solar Array Support Structure.

  6. Investigation of Abnormal Grain Growth in a Friction Stir Welded and Spin-Formed Al-Li Alloy 2195 Crew Module

    Science.gov (United States)

    Tayon, Wesley A.; Domack, Marcia S.; Hoffman, Eric K.; Hales, Stephen J.

    2013-01-01

    In order to improve manufacturing efficiency and reduce structural mass and costs in the production of launch vehicle structures, NASA is pursuing a wide-range of innovative, near-net shape manufacturing technologies. A technology that combines friction stir welding (FSW) and spin-forming has been applied to manufacture a single-piece crew module using Aluminum-Lithium (AL-Li) Alloy 2195. Plate size limitations for Al-Li alloy 2195 require that two plates be FSW together to produce a spin-forming blank of sufficient size to form the crew module. Subsequent forming of the FSW results in abnormal grain growth (AGG) within the weld region upon solution heat treatment (SHT), which detrimentally impacts strength, ductility, and fracture toughness. The current study seeks to identify microstructural factors that contribute to the development of AGG. Electron backscatter diffraction (EBSD) was used to correlate driving forces for AGG, such as stored energy, texture, and grain size distributions, with the propensity for AGG. Additionally, developmental annealing treatments prior to SHT are examined to reduce or eliminate the occurrence of AGG by promoting continuous, or uniform, grain growth

  7. Laser multi-layer cladding of Mg-based alloys

    Institute of Scientific and Technical Information of China (English)

    陈长军; 王东生; 王茂才

    2003-01-01

    By laser multi-layer cladding using a pulsed Nd-YAG irradiation the thickness of the cladding zone Mg-based alloys(ZM2 and ZM5) can reach about 1. 0 mm. The microstructure of the substrate and the cladding zone wasstudied using optical microscope, scanning electron microscopy(SEM), X-ray diffractometry(XRD) and micro hard-ness analysis. It is observed that constituent of ZM5 alloy is δ+Mg17 Al12, that of ZM2 alloy is α+MgZn+Mg9Ce.That of cladding layer ZM2 alloy(L-ZM2) is Mg+ Mg2 Zn11 +MgCe; while that of the cladding layer ZM5 alloy(L-ZM5) is Mg+Mg32 (Al, Zn)49. The hardness of the cladding area can be increased to values above HV127. Veryfine uniform microstructure and the produced new phases of nanometer/sub-micrometer order were obtained. Now,many repaired Mg-based alloy components have been passed by flying test in outside field.

  8. Laser cladding of titanium alloy coating on titanium aluminide alloy substrate

    Institute of Scientific and Technical Information of China (English)

    徐子文; 黄正; 阮中健

    2003-01-01

    A new diffusion bonding technique combined with laser cladding process was developed to join TiAl alloy to itself and Ti-alloys. In order to enhance the weldability of TiAl alloys, Ti-alloy coatings were fabricated by laser cladding on the TiAl alloy. Ti powder and shaped Ti-alloy were respectively used as laser cladding materials. The materials characterization was carried out by OM, SEM, EDS and XRD analysis. The results show that the laser cladding process with shaped Ti-alloy remedy the problems present in the conventional process with powder, such as impurities, cracks and pores. The diffusion bonding of TiAl alloy with Ti-alloy coating to itself and Ti-alloy was carried out with a Gleeble 1500 thermal simulator. The sound bonds of TiAl/TiAl, TiAl/Ti were obtained at a lower temperature and with shorter time.

  9. Laser-induced reversion of δ′ precipitates in an Al-Li alloy: Study on temperature rise in pulsed laser atom probe

    KAUST Repository

    Khushaim, Muna Saeed Amin

    2016-06-14

    The influence of tuning the laser pulse energy during the analyses on the resulting microstructure in a specimen utilizing an ultra-fast laser assisted atom probe was demonstrated by a case study of a binary Al-Li alloy. The decomposition parameters, such as the size, number density, volume fraction, and composition of δ\\' precipitates, were carefully monitored after each analysis. A simple model was employed to estimate the corresponding specimen temperature for each value of the laser energy. The results indicated that the corresponding temperatures for the laser pulse energy in the range of 10 to 80 pJ are located inside the miscibility gap of the binary Al-Li phase diagram and fall into the metastable equilibrium field. In addition, the corresponding temperature for a laser pulse energy of 100 pJ was in fairly good agreement with reported range of δ\\' solvus temperature, suggesting a result of reversion upon heating due to laser pulsing. © 2016 Wiley Periodicals, Inc.

  10. Laser-induced reversion of δ' precipitates in an Al-Li alloy: Study on temperature rise in pulsed laser atom probe.

    Science.gov (United States)

    Khushaim, Muna; Gemma, Ryota; Al-Kassab, Talaat

    2016-08-01

    The influence of tuning the laser pulse energy during the analyses on the resulting microstructure in a specimen utilizing an ultra-fast laser assisted atom probe was demonstrated by a case study of a binary Al-Li alloy. The decomposition parameters, such as the size, number density, volume fraction, and composition of δ' precipitates, were carefully monitored after each analysis. A simple model was employed to estimate the corresponding specimen temperature for each value of the laser energy. The results indicated that the corresponding temperatures for the laser pulse energy in the range of 10 to 80 pJ are located inside the miscibility gap of the binary Al-Li phase diagram and fall into the metastable equilibrium field. In addition, the corresponding temperature for a laser pulse energy of 100 pJ was in fairly good agreement with reported range of  δ' solvus temperature, suggesting a result of reversion upon heating due to laser pulsing. Microsc. Res. Tech. 79:727-737, 2016. © 2016 Wiley Periodicals, Inc.

  11. Effect of T6I6 and its modified processes on mechanical properties of novel high strength Al-Li alloy-2A97

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhi-shan; LU Zheng; XIE You-hua; WU Xiu-liang; DAI Sheng-long; LIU Chang-sheng

    2006-01-01

    Based on a novel high strength Al-Cu-Li-X alloy-2A97, the effect of T6I6 and its modified processes on the properties investigated by SEM and tensile test. The results show that when the alloy is heat treated by triple ageing, with secondary low temperature ageing at 80 ℃ after initial ageing at 155 and 150 ℃, and final re-ageing at 135 and 165 ℃, the tensile properties are close to the peak level of aged alloy in T6 temper. The addition of plastic deformation after and prior to secondary ageing favor the T1(Al2CuLi) and δ'(Al3Li) precipitation during final re-ageing at 135 and 165 ℃ corresponding to triple ageing, so the Al-Li alloy displays higher strength for the modified processes of T6I6. The microstructures consist of δ', T1 and θ"/θ' (Al2Cu) phase for single and triple aged alloy, the number density and volume fraction of δ' phase increase for T6I6 and its modified processes correspond to single ageing.

  12. Compression Buckling Behavior of Large-Scale Friction Stir Welded and Riveted 2090-T83 Al-Li Alloy Skin-Stiffener Panels

    Science.gov (United States)

    Hoffman, Eric K.; Hafley, Robert A.; Wagner, John A.; Jegley, Dawn C.; Pecquet, Robert W.; Blum, Celia M.; Arbegast, William J.

    2002-01-01

    To evaluate the potential of friction stir welding (FSW) as a replacement for traditional rivet fastening for launch vehicle dry bay construction, a large-scale friction stir welded 2090-T83 aluminum-lithium (Al-Li) alloy skin-stiffener panel was designed and fabricated by Lockheed-Martin Space Systems Company - Michoud Operations (LMSS) as part of NASA Space Act Agreement (SAA) 446. The friction stir welded panel and a conventional riveted panel were tested to failure in compression at the NASA Langley Research Center (LaRC). The present paper describes the compression test results, stress analysis, and associated failure behavior of these panels. The test results provide useful data to support future optimization of FSW processes and structural design configurations for launch vehicle dry bay structures.

  13. Influence of alloy ingredients on mechanical properties of ternary boride hard alloy clad materials

    Institute of Scientific and Technical Information of China (English)

    LIU Fu-tian; SONG Shi-xue; YANG Jun-ru; HUANG Wei-ling; HUANG Chuan-zhen; CHENG Xin; LI Zhao-qian

    2004-01-01

    Using Mo, B-Fe alloy and Fe powders as raw materials, and adding C, Cr and Ni ingredients, respectively, or C, Cr and Ni mixed powders, ternary boride hard alloy clad materials was prepared on Q235 steel substrate by means of in-situ reaction and vacuum liquid phase sintering technology. The influence of alloy ingredients on the mechanical properties of ternary boride hard alloy clad materials was investigated. The results indicate that a mixture of 0.8% C, 5% Cr and 2% Ni ingredients gives a ternary boride hard alloy clad material with optimal mechanical properties, such as high transverse rupture strength, high hardness and good wear resistance.

  14. Multilayer Clad Plate of Stainless Steel/Aluminum/Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    YUAN Jiawei; PANG Yuhua; LI Ting

    2011-01-01

    The 3, 5, 20 layer clad plate from austenitic stainless steel, pure aluminum and aluminum alloy sheets were fabricated in different ways. The stretch and interface properties were measured. The result shows that 20 layer clad plate is better than the others. Well-bonded clad plate was successfully obtained in the following procedure: Basic clad sheet from 18 layer A11060/A13003sheets was firstly obtained with an initial rolling reduction of 44% at 450 ℃, followed by annealing at 300 ℃, and then with reduction of 50% at 550 ℃ from STS304 on each side. The best 20 layer clad plate was of 129 MPa bonding strength and 225 MPa stretch strength.

  15. Laser cladding of Ni-based alloy on stainless steel

    Institute of Scientific and Technical Information of China (English)

    XUE Chun-fang; TIAN Xin-li; TAN Yong-sheng; WU Zhi-yuan

    2004-01-01

    The coatings on a stainless steel substrate were conducted by laser cladding of Ni-based alloy, using a 5 kW continuous wave CO2 flow transverse laser. SEM, EDX and X-ray diffraction were used to analyze the microstructure and constituent phases of the obtained coatings by laser cladding with direct injection of the powder into the melt pool. Solidification planar, cellular and dendrite structures were observed in Ni-based alloy coating. There exists an optimum metallurgical bond between Ni-based laser cladding layer and the base material. The high hardness of the Ni-based alloy coating is attributed to the presence of M7C3-type carbides (essentially chromium-riched carbide) dispersed in the γ(Ni,Fe) phase matrix.

  16. Additive manufacturing of metal alloy for aerospace by means of Powder Laser Cladding: station tuning and clad characterization

    OpenAIRE

    Fierro, Ilaria

    2016-01-01

    2014 - 2015 This thesis investigates the application of continuous coaxial laser cladding by powder injection as repair and cover process. The investigation aimed to check the possibility of repairing a V-groove geometry on a substrate of AA2024 and A357 aluminum alloy. Chapter one is an introduction to the laser cladding. This presents a general overview of the laser cladding methods and some applications for the processes. In the second chapter, the laser cladding process is analys...

  17. Influence of aging at 180C on the corrosion behaviour of a ternary Al-Li-Zr alloy

    DEFF Research Database (Denmark)

    Ambat, Rajan; Prasad, R.K.; Dwarakadasa, E.S.

    1994-01-01

    The influence of aging at 180 °C on the corrosion behaviour of an Al-1.5%Li-0.1%Zr alloy has been studied using weight loss, open circuit potential (OCP) measurements and potentiodynamic polarization measurements in 3.5% NaCl solution. Corrosion rates obtained from weight loss and Icorr values...

  18. Effect of SiC reinforcement on the deformation and fracture micromechanisms of Al-Li alloys

    Science.gov (United States)

    Poza; Llorca

    1999-11-01

    The effect of SiC reinforcement on the microstructure of a naturally aged 8090 Al alloy as well as on the deformation and fracture micromechanisms was investigated. To this end, the microstructural characteristics (grain and reinforcement morphology, precipitate structure) were determined in the unreinforced alloy and in the composite reinforced with 15 vol.% SiC particles. The materials were tested under monotonic tension and fully reversed cyclic deformation and then carefully analysed through scanning and transmission electron microscopy to find the dominant deformation and failure processes for each material and loading condition. It was found that the dispersion of the SiC particles restrained the formation of elongated grains during extrusion and inhibited the precipitation of Al3Li. As a result, the plastic deformation in the composite was homogeneous, while strain localization in slip bands was observed in the unreinforced alloy specimens tested in tension and in fatigue. The unreinforced alloy failed by transgranular shear along the slip bands during monotonic deformation, whereas fracture was initiated by grain boundary delamination, promoted by the stress concentrations induced by the slip bands, during cyclic deformation. The fracture of the composite was precipitated by the progressive fracture of the SiC reinforcements during monotonic and cyclic deformation.

  19. Effect of equal channel angular extrusion on the microstructure and superplasticity of an Al-Li alloy

    Science.gov (United States)

    Salem, H. G.; Lyons, J. S.

    2002-08-01

    This research investigates the use of equal channel angular extrusion (ECAE) processing to produce a superplastic form of the aluminum alloy 2098. The starting material was a hot-rolled and precipitation-hardened plate with elongated grains of width 67-92 µm, and a composition in weight percent of 2.2% Li, 1.3% Cu, 0.73% Mg, 0.05% Zr, balance Al. Microstructural evolution was investigated with optical and transmission electron microscopy (TEM) and microhardness measurements after each step of a multipass ECAE process. ECAE produced a submicron grain structure with an average size of about 0.5 µm. The sub-grain microstructure size was a function of the magnitude of the input strain and the extrusion temperature. Misorientation angles of the developed submicron structure increase with increasing number of passes at warm working temperatures. Superplastic behavior of the ECAE-processed alloy was achieved. However, the low zirconium content of the 2098 alloy resulted in grain growth of the refined structure at the superplastic processing temperatures, placing a lower limit on the deformation rates that can be used.

  20. The effect of vibrational entropy on the solubility and stability of ordered Al3Li phases in Al-Li alloys

    Science.gov (United States)

    Mao, Zugang; Seidman, David N.; Wolverton, C.

    2013-10-01

    The solubility and stability of three possible ordered Al3Li structures in Al-Li alloys are studied using first-principles calculations: δ'-Al3Li(L12), δ-Al3Li(DO22), and β-Al3Li(DO3). We find that δ'-Al3Li(L12) is the most stable phase and β-Al3Li(DO3) is energetically unfavorable. The vibrational formation entropy makes a significant contribution to the solubility for all three ordered Al3Li structures and yields a 1.6-fold increase in the calculated solubility of δ'-Al3Li(L12), a 1.8-fold increase for δ-Al3Li(DO22), and a 2.5-fold increase for β-Al3Li(DO3). The solubility of δ'-Al3Li(L12) is greater than those of δ-Al3Li(DO22) and β-Al3Li(DO3), and the δ'-Al3Li(L12) solvus curve is in good agreement with the experimental one.

  1. Laser cladding of Ni-based alloy on copper substrate

    Institute of Scientific and Technical Information of China (English)

    Fang Liu; Changsheng Liu; Xingqi Tao; Suiyuan Chen

    2006-01-01

    The laser cladding of Ni1015 alloy on Cu substrate was prepared by a high power continuous wave CO2 laser. Its microstructure was analyzed by optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The average microhardness of the cladding coating was Hv 280, which was almost three times of that of the Cu substrate (Hv 85). OM and SEM observations showed that the obtained coating had a smooth and uniform surface, as well as a metallurgical combination with the Cu substrate without cracks and pores at the interface. With the addition of copper into the nickel-based alloy, the differences of thermal expansion coefficient and melting point between the interlayer and cladding were reduced, which resulted in low stresses during rapid cooling. Moreover, large amount of (Cu, Ni) solid solution formed a metallurgical bonding between the cladding coating and the substrate, which also relaxed the stresses, leading to the reduction of interfacial cracks and pores after laser cladding.

  2. Cladding Alloys for Fluoride Salt Compatibility Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Muralidharan, Govindarajan [ORNL; Wilson, Dane F [ORNL; Santella, Michael L [ORNL; Holcomb, David Eugene [ORNL

    2011-05-01

    This interim report provides an overview of several candidate technologies for cladding nickel-based corrosion protection layers onto high-temperature structural alloys. The report also provides a brief overview of the welding and weld performance issues associated with joining nickel-clad nickel-based alloys. From the available techniques, two cladding technologies were selected for initial evaluation. The first technique is a line-of-sight method that would be useful for coating large structures such as vessel interiors or large piping. The line-of-sight method is a laser-based surface cladding technique in which a high-purity nickel powder mixed into a polymer binder is first sprayed onto the surface, baked, and then rapidly melted using a high power laser. The second technique is a vapor phase technique based on the nickel-carbonyl process that is suitable for coating inaccessible surfaces such as the interior surfaces of heat exchangers. The final project report will feature an experimental evaluation of the performance of the two selected cladding techniques.

  3. Preparation and Cycling Performance of Iron or Iron Oxide Containing Amorphous Al-Li Alloys as Electrodes

    Directory of Open Access Journals (Sweden)

    Franziska Thoss

    2014-12-01

    Full Text Available Crystalline phase transitions cause volume changes, which entails a fast destroying of the electrode. Non-crystalline states may avoid this circumstance. Herein we present structural and electrochemical investigations of pre-lithiated, amorphous Al39Li43Fe13Si5-powders, to be used as electrode material for Li-ion batteries. Powders of master alloys with the compositions Al39Li43Fe13Si5 and Al39Li43Fe13Si5 + 5 mass-% FeO were prepared via ball milling and achieved amorphous/nanocrystalline states after 56 and 21.6 h, respectively. In contrast to their Li-free amorphous pendant Al78Fe13Si9, both powders showed specific capacities of about 400 and 700 Ah/kgAl, respectively, after the third cycle.

  4. Co-strengthening contribution of δ' and T1 precipitates in Al-Li alloys 2090 and 2090+Ce

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhilong; LIU Lin; CHEN Zheng

    2006-01-01

    The microstructure of dislocation in two kinds of aluminum-lithium alloys 2090 and 2090 + Ce was observed by means of TEM technology. The contributions of δ' and T1 precipitates to strength were separately calculated by using the results of quantitative metallography and analysis of micro-deformation behavior; the co-strengthening effect of δ' and T1precipitates was studied. The results show that the adding relationship of co-strengthening of δ' and T1 is in accordance with q = 1.4 form at the near peak-aged condition, i.e., △τ1.4 p = △τ1.4 δ' + △τ1.4 T1; but the adding relationship is approximately a linear relation (q = 1) at the under-aged condition and becomes the parabola form when over-aged (q = 2). The adding relationship of co-strengthening contribution of δ' and T1 is obviously dependent on aging time.

  5. Characterization of Precipitation in Al-Li Alloy AA2195 by means of Atom Probe Tomography and Transmission Electron Microscopy

    KAUST Repository

    Khushaim, Muna

    2015-05-19

    The microstructure of the commercial alloy AA2195 was investigated on the nanoscale after conducting T8 tempering. This particular thermomechanical treatment of the specimen resulted in the formation of platelet-shaped T 1 Al 2 CuLi / θ ′ Al 2 Cu precipitates within the Al matrix. The electrochemically prepared samples were analyzed by scanning transmission electron microscopy and atom probe tomography for chemical mapping. The θ ′ platelets, which are less than 2 nm thick, have the stoichiometric composition consistent with the expected Al 2 Cu equilibrium composition. Additionally, the Li distribution inside the θ ′ platelets was found to equal the same value as in the matrix. The equally thin T 1 platelet deviates from the formula (Al 2 CuLi) in its stoichiometry and shows Mg enrichment inside the platelet without any indication of a higher segregation level at the precipitate/matrix interface. The deviation from the (Al 2 CuLi) stoichiometry cannot be simply interpreted as a consequence of artifacts when measuring the Cu and Li concentrations inside the T 1 platelet. The results show rather a strong hint for a true lower Li and Cu contents, hence supporting reasonably the hypothesis that the real chemical composition for the thin T 1 platelet in the T8 tempering condition differs from the equilibrium composition of the thermodynamic stable bulk phase.

  6. Calculation of electric field effects on the Gibbs free energy of the Al-Li-Mg alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the Thomas-Fermi model the calculation methods of the monatomic Gibbs free energy were found.The interior potential boundary condition under electric field was defined. The calculation methods of Gibbs free energy for the monatomic, compound, and solid solution with electric field were set up. Under the influence of electric field, the Gibbs free energy of A1 is the most sensitive, followed by those of Li and Mg. At the solution temperature the Gibbs free energies of Al3Li and its elements under electric field are not symmetrical about the zero point of electric field, whereas at the aging temperature their values are symmetrical about the zero point of electric field. At the solution temperature near the zero point of electric field, the Gibbs free energy of Al3Li is higher than that of Al-2.14%Li. And at 460 K the Gibbs free energy of A13Li is lower than that of Al-2.14wt.%Li under electric field. The Gibbs free energy of 1420 alloy decreases from both sides of electric field to the zero point at the aging temperature.

  7. Coarsening kinetics, thermodynamic properties, and interfacial characteristics of δ' precipitates in Al-Li alloys taking into account the Gibbs-Thomson effect

    Science.gov (United States)

    Tsao, C.-S.; Chen, C.-Y.; Huang, J.-Y.

    2004-11-01

    The structure factor model of small-angle x-ray scattering (SAXS) analysis is validated herein by transmission electron microscopy (TEM) result regarding the volume fraction and size of δ' precipitates. The kinetic behaviors of the number density and volume fraction of δ' precipitates in Al-Li alloys during the coarsening stage are quantitatively investigated by SAXS. The results indicate that the conventional kinetic law must be replaced by a more general equation that incorporates the Gibbs-Thomson effect and the time-dependence of the volume fraction during Ostwald ripening. This work also proposes new methods that combine the Gibbs-Thomson effect and the traditional SAXS equation to resolve more reliably and model independently the interfacial energy, the concentration of solute Li in the α matrix in equilibrium with δ' particles of a nanoscale radius Cαr , the equilibrium solubility of the α phase Ceα and the equilibrium concentration of δ' particles. The Gibbs-Thomson effect considers the effects of the interfacial energy and particle size on the equilibrium concentration. This effect quantitatively clarifies that the Cαr value is size-dependent and is related to the Ceα value and the interfacial energy. The traditional SAXS equation determines the Li concentrations in the δ' particles and the matrix from the measured scattering contrast. The traditionally determined solubility is in fact the Cαr value and is mistakenly regarded as the equilibrium concentration Ceα (corresponding to the radius is infinite). These results are compared to other results obtained by SAXS, TEM, and calculation. The time evolution of the transition interfacial layers between δ' particles and the matrix is extensively investigated using SAXS.

  8. The Enhanced Effect of Optical Emission from Laser Induced Breakdown Spectroscopy of an Al-Li Alloy in the Presence of Magnetic Field Confinement

    Science.gov (United States)

    Liu, Ping; Hai, Ran; Wu, Ding; Xiao, Qingmei; Sun, Liying; Ding, Hongbin

    2015-08-01

    In this paper, the influence of magnetic field strength on laser-induced breakdown spectroscopy (LIBS) has been investigated for various pressures. The plasma plume was produced by employing Q-switch Nd:YAG laser ablation of an Al-Li alloy operating at a 1064 nm wavelength. The results indicated that the LIBS intensity of the Al and Li emission lines is boosted with an increase of magnetic strength. Typically, the intensity of the Al I and Li I spectral emissions can be magnified by 1.5-3 times in a steady magnetic field of 1.1 T compared with the field-free case. Also, in this investigation we recorded time-resolved images of the laser-produced plume by employing a fast ICCD camera. The results show that the luminance of the plasma is enhanced and the time of persistence is increased significantly, and the plasma plume splits into two lobes in the presence of a magnetic field. The probable reason for the enhancement is the magnetic confinement effect which increases the number density of excited atoms and the population of species in a high energy state. In addition, the electron temperature and density are also augmented by the magnetic field compared to the field-free case. supported by the National Magnetic Confinement Fusion Science Program of China (No. 2013GB109005) and National Natural Science Foundation of China (No. 11175035), Chinesisch-Deutsches Forschungs Project (GZ768), the Fundamental Research Funds for the Central Universities, China (Nos. DUT12ZD(G)01, (DUT14ZD(G)04), MMLab Research Project (DP1051208)

  9. Effect of the composition of Al-Li alloys on the quantitative relation between the δ'(Al3Li), S1(Al2MgLi), and T1(Al2CuLi) phases

    Science.gov (United States)

    Betsofen, S. Ya.; Antipov, V. V.; Grushin, I. A.; Knyazev, M. I.; Khokhlatova, L. B.; Alekseev, A. A.

    2015-01-01

    Al-Li alloys are considered. A quantitative approach to the determination of the ratio of the fractions of the binary and ternary intermetallic phases in Al-Mg(Cu)-Li alloys is developed on the basis of chemical and phase composition balance equations and the experimentally measured lattice parameter of the α solid solution. The ratio of the fractions of the δ'(Al3Li) and S1(T1) phases in Al-Mg(Cu)-Li alloys is shown to be determined by the ratio of the mole fractions of Li and Mg(Cu). Equations are proposed for calculating the weight fractions of the S1(Al2MgLi), T1(Al2CuLi) and δ'(Al3Li) phases in domestic and foreign Al-Mg-Li alloys 1420, 1424, 5090 and Al-Cu-Li alloys 1440, 1460, 1461, 1441, 1469, 2090, 2095, 8090, and Weldalite 049.

  10. Gradient microstructure in laser clad TiC-reinforced Ni-alloy composite coating

    NARCIS (Netherlands)

    Pei, Y.T.; Zuo, T.C.

    1998-01-01

    A gradient TiC–(Ni alloy) composite coating was produced by one step laser cladding with pre-placed mixture powder on a 1045 steel substrate. The clad layers consisted of TiC particles, γ-Ni primary dendrites and interdendritic eutectics. From the bottom to the top of the clad layer produced at 2000

  11. Evaluation of Pressurization Fatigue Life of 1441 Al-li Fuselage Panel

    Science.gov (United States)

    Bird, R. Keith; Dicus, Dennis I.; Fridlyander, Joseph; Davydov, Valentin

    1999-01-01

    A study was conducted to evaluate the pressurization fatigue life of fuselage panels with skins fabricated from 1441 Al-Li, an attractive new Russian alloy. The study indicated that 1441 Al-Li has several advantages over conventional aluminum fuselage skin alloy with respect to fatigue behavior. Smooth 1441 Al-Li sheet specimens exhibited a fatigue endurance limit similar to that for 1163 Al (Russian version of 2024 Al) sheet. Notched 1441 Al-Li sheet specimens exhibited greater fatigue strength and longer fatigue life than 1163 Al. In addition, Tu-204 fuselage panels fabricated by Tupolev Design Bureau using Al-Li skin and ring frames with riveted 7000-series aluminum stiffeners had longer pressurization fatigue lives than did panels constructed from conventional aluminum alloys. Taking into account the lower density of this alloy, the results suggest that 1441 Al-Li has the potential to improve fuselage performance while decreasing structural weight.

  12. Wear resistance and hot corrosion behaviour of laser cladding Co-based alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    2Cr13 stainless steel was surface cladded with Co-based alloy using a high power carbon dioxide laser. The microstructure, wear resistance and corrosion properties of the clad layer were investigated. It is found that the high temperature corrosion behavior and wearing resistant property of the clad layer are 3 and 2.5 times higher than those of the parent metal. Under the high temperature molten lead sulphate salt corrosion condition, the clad layer fails by spalling which is caused by intergrannular corrosion within the clad layer. The fine dendritic structure and the oxide help to retard the penetration of the sulphur ion that induces the intergrannular corrosion.

  13. Solution chemistry effects on the stress corrosion cracking behavior of alloy 2090 (Al-Li-Cu) and alloy 2024 (Al-Cu-Mg)

    Science.gov (United States)

    Moran, James P.; Stoner, Glenn E.

    1989-01-01

    The SCC initiation behavior of alloys 2090 and 2024 is examined in various NaCl-based environments. The pre-exposure and bulk/local solution chemistry effects discovered by Holroyd et al. (1986) are investigated, with emphasis on the effect of bulk solution chemistries and atmospheric CO2 on the occluded cell environment and the role of the occluded environment in the crack initiation and early-stage propagation processes. It was found that constant immersion in NaCl does not promote SCC in alloy 2090 or alloy 2024. Upon removal from NaCl, SCC is quickly facilitated, but only in the presence of atmospheric CO2. The need for CO2 is attributed to an increase in carbonate concentrations, eventually allowing passivation of blunted fissures by precipitation of Li2CO3. It is inferred that any effects due to aging are small in magnitude, relative to the effects of subtle changes in the bulk/local solution chemistries.

  14. 时效处理对Al-Li二元合金力学性能的影响%Influence of aging treatment on mechanical properties of Al-Li binary alloys

    Institute of Scientific and Technical Information of China (English)

    梁宇; 王赫男; 刘春忠

    2015-01-01

    Al-1Li,Al-2Li and Al-3Li binary alloys were prepared by using vacuum induction melting fur-nace. The as-cast microstructure was observed with an optical microscopy and the phase transition tempera-tures of the three alloys were determined by differential scanning calorimetry( DSC). After solution and ag-ing treatment,the hardness of the three alloy samples were measured by using Vickers hardness tester. The Al-Li alloy samples were selected with different aging time and tensile test was conducted. The fracture mor-phologies of the samples were observed by scanning electron microscope( SEM ). The results indicate that both Al-2 Li alloy and Al-3 Li alloy have aging hardening and strengthening effects but Al-1 Li alloy does not. The maximum tensile strength of Al-1Li,Al-2Li and Al-3Li binary alloys are 63MPa,162MPa and 298MPa respectively. The tensile strength is increased and the toughness of Al-Li alloys is decreased with the growth of Li element. The fracture mechanism of alloys is changed to the brittle fracture from the ductile fracture due to Li addition.%采用真空感应熔炼炉制备Al-1Li、Al-2Li和Al-3Li二元合金,用金相显微镜观察其铸态组织,并用DSC确定其相转变温度。对3种合金进行固溶和时效处理,用维氏硬度计测量试样的硬度。选择具有不同时效时间的Al-Li合金进行拉伸实验,并用SEM观察断口形貌。结果表明:除Al-1Li合金外,Al-2Li和Al-3Li合金具有明显时效硬化和强化效应;Al-1Li、Al-2Li和Al-3Li合金的最大抗拉强度分别为63 MPa、162 MPa和298 MPa;合金元素Li在提高Al-Li合金强度的同时,导致其韧性降低,断裂由韧性向脆性转变。

  15. The Evolution of Al-Li Base Products for Aerospace and Space Applications

    Science.gov (United States)

    Rioja, Roberto J.; Liu, John

    2012-09-01

    A technical review of the physical, mechanical, and metallurgical variables that have influenced performance of Al-Li based alloys over the last 50 years is presented. First, the historic evolution of different alloys is discussed. Then, the microstructural features responsible for different mechanical properties are identified and discussed. The role of alloying additions is discussed. The shortcomings of a 2nd generation Al-Li alloys are introduced and the key alloy design principles used to overcome these are discussed. Finally, the performance parameters that play a major role in sizing several aircraft and space craft components are reviewed in a chronological perspective and compared with 3rd-generation Al-Li alloys. It is concluded that significant improvements have been made to position Al-Li alloys to enable improved performance of next generation of air and space craft.

  16. Ceramic Coatings for Clad (The C3 Project): Advanced Accident-Tolerant Ceramic Coatings for Zr-Alloy Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Sickafus, Kurt E. [Univ. of Tennessee, Knoxville, TN (United States); Wirth, Brian [Univ. of Tennessee, Knoxville, TN (United States); Miller, Larry [Univ. of Tennessee, Knoxville, TN (United States); Weber, Bill [Univ. of Tennessee, Knoxville, TN (United States); Zhang, Yanwen [Univ. of Tennessee, Knoxville, TN (United States); Patel, Maulik [Univ. of Tennessee, Knoxville, TN (United States); Motta, Arthur [Pennsylvania State Univ., University Park, PA (United States); Wolfe, Doug [Pennsylvania State Univ., University Park, PA (United States); Fratoni, Max [Univ. of California, Berkeley, CA (United States); Raj, Rishi [Univ. of Colorado, Boulder, CO (United States); Plunkett, Kenneth [Univ. of Colorado, Boulder, CO (United States); Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States); Hollis, Kendall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nelson, Andy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stanek, Chris [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Comstock, Robert [Westinghouse Electric Corporation, Pittsburgh, PA (United States); Partezana, Jonna [Westinghouse Electric Corporation, Pittsburgh, PA (United States); Whittle, Karl [Univ. of Sheffield (United Kingdom); Preuss, Michael [Univ. of Manchester (United Kingdom); Withers, Philip [Univ. of Manchester (United Kingdom); Wilkinson, Angus [Univ. of Oxford (United Kingdom); Donnelly, Stephen [Univ. of Huddersfield (United Kingdom); Riley, Daniel [Australian Nuclear Science and Technology Organisation, Syndney (Australia)

    2017-02-14

    The goal of this NEUP-IRP project is to develop a fuel concept based on an advanced ceramic coating for Zr-alloy cladding. The coated cladding must exhibit demonstrably improved performance compared to conventional Zr-alloy clad in the following respects: During normal service, the ceramic coating should decrease cladding oxidation and hydrogen pickup (the latter leads to hydriding and embrittlement). During a reactor transient (e.g., a loss of coolant accident), the ceramic coating must minimize or at least significantly delay oxidation of the Zr-alloy cladding, thus reducing the amount of hydrogen generated and the oxygen ingress into the cladding. The specific objectives of this project are as follows: To produce durable ceramic coatings on Zr-alloy clad using two possible routes: (i) MAX phase ceramic coatings or similar nitride or carbide coatings; and (ii) graded interface architecture (multilayer) ceramic coatings, using, for instance, an oxide such as yttria-stabilized zirconia (YSZ) as the outer protective layer. To characterize the structural and physical properties of the coated clad samples produced in 1. above, especially the corrosion properties under simulated normal and transient reactor operating conditions. To perform computational analyses to assess the effects of such coatings on fuel performance and reactor neutronics, and to perform fuel cycle analyses to assess the economic viability of modifying conventional Zr-alloy cladding with ceramic coatings. This project meets a number of the goals outlined in the NEUP-IRP call for proposals, including: Improve the fuel/cladding system through innovative designs (e.g. coatings/liners for zirconium-based cladding) Reduce or eliminate hydrogen generation Increase resistance to bulk steam oxidation Achievement of our goals and objectives, as defined above, will lead to safer light-water reactor (LWR) nuclear fuel assemblies, due to improved cladding properties and built-in accident resistance, as well as

  17. A vertical type twin roll caster for an aluminium alloy clad strip

    OpenAIRE

    T. Haga; Nakamura, R; Kuma, S; H. Watari

    2013-01-01

    Purpose: of this paper: Twin roll casters that can cast two layers and three layers clad strip of aluminium alloys were invented. One of the purposes of this paper is to report that the two layers and three layers clad strip could be cast by the twin roll caster of this study. The investigation of the characters of these casters and the clad strips was purpose of this paper, too. The connecting at the interface between the strips was most important in the casting of the clad strip. Therefore,...

  18. Viscosity and electrical resistivity of Al-Li melts

    Science.gov (United States)

    Kononenko, V. I.; Razhabov, A. A.; Ryabina, A. V.

    2011-08-01

    The kinematic viscosity and electrical resistivity of Al-Li alloys in the liquid state are studied by a combined electrodeless method. Some theoretical calculations performed to determine the viscosity and electrical resistance by comparing the calculated and experimental data are estimated.

  19. Deep surface rolling for fatigue life enhancement of laser clad aircraft aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, W., E-mail: wyman.zhuang@dsto.defence.gov.au [Aerospace Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, Victoria 3207 (Australia); Liu, Q.; Djugum, R.; Sharp, P.K. [Aerospace Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, Victoria 3207 (Australia); Paradowska, A. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2232 (Australia)

    2014-11-30

    Highlights: • Deep surface rolling as a post-repair enhancement technology was applied to the laser cladded 7075-T651 aluminium alloy specimens that simulated corrosion damage blend-out repair. • The residual stresses induced by the deep surface rolling process were measured. • The deep surface rolling process can introduce deep and high magnitude compressive residual stresses beyond the laser clad and substrate interface. • Spectrum fatigue test showed the fatigue life was significantly increased by deep surface rolling. - Abstract: Deep surface rolling can introduce deep compressive residual stresses into the surface of aircraft metallic structure to extend its fatigue life. To develop cost-effective aircraft structural repair technologies such as laser cladding, deep surface rolling was considered as an advanced post-repair surface enhancement technology. In this study, aluminium alloy 7075-T651 specimens with a blend-out region were first repaired using laser cladding technology. The surface of the laser cladding region was then treated by deep surface rolling. Fatigue testing was subsequently conducted for the laser clad, deep surface rolled and post-heat treated laser clad specimens. It was found that deep surface rolling can significantly improve the fatigue life in comparison with the laser clad baseline repair. In addition, three dimensional residual stresses were measured using neutron diffraction techniques. The results demonstrate that beneficial compressive residual stresses induced by deep surface rolling can reach considerable depths (more than 1.0 mm) below the laser clad surface.

  20. Laser cladding of Al + Ir powders on ZM5 magnesium base alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Laser cladding of preplaced Al + Ir powders on a ZM5 magnesium alloy was performed to enhance the corrosion resistance of the ZM5 magnesium alloy. A metallurgical bond was obtained at the coating/substrate interface. The corrosion potential (Ecorr) of the laser cladded sample was 169 mV positive to that of the untreated ZM5 substrate, while the corrosion current (Icorr) was some one order of magnitude lower. The laser cladded sample, unlike the untreated ZM5 substrate,showed a passive region in the polarization plot. Immersion tests confirmed that the corrosion resistance of the laser cladded ZM5 sample was significantly enhanced in 3.5 wt.% NaCl solution. The Al-rich phases of AlIr, Mg17Al12, and Al formed in the cladding layer and the rapid solid characteristics were contributed to the improved corrosion behavior of the coating.

  1. 铝锂合金中原子簇聚和有序化的计算机模拟研究%Investigations on Ordering and Atom Clustering in Al-Li Alloy by Computer Simulation

    Institute of Scientific and Technical Information of China (English)

    李晓玲; 陈铮; 王永欣; 胡明娟

    2006-01-01

    通过计算机模拟对铝锂合金时效过程中的有序化和原子簇聚进行了研究.长程序参数和成分偏离序参数通过锂原子格点占位几率计算得出.结果表明:随合金成分由相图上的亚稳区向失稳区转变,有序化与原子簇聚过程相比逐渐加快,而相变孕育期逐渐缩短.%Investigations on the ordering and atom clustering in aged binary Al-Li alloy have been carried out by computer simulation. The long range order parameter (lro.) and composition deviation order parameter were calculated from single-site occupation probabilities of Li atom. The results show that as the composition of the alloy increases from metastable region to instable region in the phase diagram ordering occurs faster than atom clustering gradually and the incubation period of the phase transformation is shortened.

  2. Properties and features of structure formation CuCr-contact alloys in electron beam cladding

    Energy Technology Data Exchange (ETDEWEB)

    Durakov, Vasiliy G., E-mail: electron@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Dampilon, Bair V., E-mail: dampilon@ispms.tsc.ru, E-mail: gnusov@rambler.ru; Gnyusov, Sergey F., E-mail: dampilon@ispms.tsc.ru, E-mail: gnusov@rambler.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2014-11-14

    The microstructure and properties of the contact CuCr alloy produced by electron-beam cladding have been investigated. The effect of the electron beam cladding parameters and preheating temperature of the base metal on the structure and the properties of the coatings has been determined. The bimodal structure of the cladding coating has been established. The short circuit currents tests have been carried out according to the Weil-Dobke synthetic circuit simulating procedure developed for vacuum circuit breakers (VCB) test in real electric circuits. Test results have shown that the electron beam cladding (EBC) contact material has better breaking capacity than that of commercially fabricated sintered contact material. The application of the technology of electron beam cladding for production of contact material would significantly improve specific characteristics and reliability of vacuum switching equipment.

  3. Cladding of Advanced Al Alloys Employing Friction Stir Welding

    NARCIS (Netherlands)

    Stelt, van der A.A.; Bor, T.C.; Geijselaers, H.J.M.; Akkerman, R.; Boogaard, van den A.H.

    2013-01-01

    In this paper an advanced solid state cladding process, based on Friction Stir Welding, is presented. The Friction Surface Cladding (FSC) technology enables the deposition of a solid-state coating using filler material on a substrate with good metallurgical bonding. A relatively soft AA1050 filler m

  4. Application of the diagrams of phase transformations during aging for optimizing the aging conditions for V1469 and 1441 Al-Li alloys

    Science.gov (United States)

    Lukina, E. A.; Alekseev, A. A.; Antipov, V. V.; Zaitsev, D. V.; Klochkova, Yu. Yu.

    2009-12-01

    To describe the changes in the phase composition of alloys during aging, it is convenient to construct TTT diagrams on the temperature-aging time coordinates in which time-temperature regions of the existence of nonequilibrium phases that form during aging are indicated. As a rule, in constructing the diagrams of phase transformations during aging (DPTA), time-temperature maps of properties are plotted. A comparison of the diagrams with maps of properties allows one to analyze the effect of the structure on the properties. In this study, we analyze the DPTAs of V1469 (Al-1.2 Li-0.46 Ag-3.4 Cu-0.66 Mg) and 1441 (Al-1.8 Li-1.1 Mg-1.6 Cu, C Mg/ C Cu ≈ 1) alloys. Examples of the application of DPTA for the development of steplike aging conditions are reported.

  5. CP276铝-锂合金的固溶温度研究%Study on Solid Solution Treatment Temperature for Al-Li Alloy CP276

    Institute of Scientific and Technical Information of China (English)

    谢绍俊

    2001-01-01

    探讨了固溶温度对CP276铝-锂合金显微组织和力学性能的影响.研究证明,提高固溶温度可以促进Cu、Li原子向基体溶解,进而提高合金时效的沉淀强化效果.并且发现,该合金经固溶处理后可得到未完全再结晶组织,这种微观组织将对基体产生"组织强化效应",随着固溶温度升高,合金的再结晶程度也有所增加,从而使组织强化效应受到削弱.力学性能测定结果显示,CP276合金的理想固溶温度为530℃左右.%The effect of solid solution treatment (SST) temperature on the microstructure and mechanical properties for aluminium-lithium alloy CP276 was experimentally explored. It is verified that the increasing of SST temperature promoted the dissolving of Cu, Li atoms to solid solution matrix, and hence improved the ageing strengthening effect upon the alloy. It is also found that, incompletely recrystallized structure could be obtained after solid solution treatment, which helpfully providing "structure-strengthening effect" for this alloy. However, the recrystallization degree improved along with the increasing of SST temperature, making the structure-strengthening effect somewhat weakened. The results of mechanical tensile tests show the desirable SST temperature for alloy CP276 is about 530 ℃.

  6. Analysis of Ordering Process in an Al-Li Alloy by a Newly Developed Method of Degree of Order Determination Using High-Resolution Transmission Electron Micrographs

    Science.gov (United States)

    Kobayashi, Sengo; Nakai, Kiyomichi; Ohmori, Yasuya

    2012-12-01

    Ordering processes of an Al-11.7 at. pct Li alloy in the early stage of aging have been investigated quantitatively by means of a newly proposed technique to determine the degree of order in a nanoscale area by using high-resolution transmission electron microscopy (TEM). After solid solution treatment at 833 K (560 °C) for 1.8 ks, the specimen was quenched into iced brine. The specimen exhibited congruent ordering. It was continuously heated at a rate of 0.17 Ks-1 (0.17 °C s-1). During heating to 673 K (400 °C), the reactions occurred in the following sequences: progress of the congruent ordering, partition of Li atoms around the antiphase domain boundaries, phase separation into Li-rich and Li-lean regions toward equilibria, and dissolution of δ' phase.

  7. Influence of processing parameters on microstructure and wear resistance of Ti+TiC laser clad layer on titanium alloy

    Institute of Scientific and Technical Information of China (English)

    WU Wan-liang; SUN Jian-feng; DONG Sheng-min; LIU Rongx-iang

    2006-01-01

    Laser cladding experiments were carried out on Ti-6Al-4V alloy with Ti+33%TiC(volume fraction) powders. Laser processing parameters were studied systematically to investigate the influences on the surface quality. Microstructure, microhardness and wear resistance of the clad layer were evaluated. The results show that the laser parameter has considerable influence on microstructure and wear resistance of laser clad layer. With the optimized technical parameters, a clad layer with good surface quality and uniform microstructure was obtained. The microhardness of the clad layer HV0.2 is 1 080, and the wear rate is reduced by 57 times.

  8. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings - phase II

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Stanko, G.J. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1996-08-01

    In Phase I a variety of developmental and commercial tubing alloys and claddings were exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase II (in situ testing) has exposed samples of 347, RA-8511, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 modified, 800HT, NF 709, 690 clad, and 671 clad for over 10,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were installed on an air-cooled, retractable corrosion probe, installed in the reheater cavity, and controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. Samples of each alloy will be exposed for 4000, 12,000, and 16,000 hours of operation. The results will be presented for the metallurgical examination of the corrosion probe samples after 4000 hours of exposure.

  9. Laser cladding of ZrO2-(Ni alloy) composite coating

    NARCIS (Netherlands)

    Pei, Y.T.; Ouyang, J.H.; Lei, T.C.

    1996-01-01

    The microstructure of laser-clad 60 vol.% ZrO2 (partially stabilized with 2 mol% Y2O3) plus 40 vol.% Ni alloy composite coating on steel 1045 was investigated by scanning electron microscopy, electron probe microanalysis, X-ray diffraction, energy-dispersive X-ray analysis and microhardness tests. T

  10. Microstructure of laser-clad SiC-(Ni alloy) composite coating

    NARCIS (Netherlands)

    Pei, Y.T.; Ouyang, J.H.; Lei, T.C.; Zhou, Y.

    1995-01-01

    The laser cladding technique was used to produce Ni alloy coatings with different SiC particle (SiCp) contents on steel 1045. The complete dissolution of SiCp took place during laser melting and led to a microstructural evolution of the coatings associated with the SiCp content. M7X3 or M23X6-type c

  11. Laser surface cladding of ZM5 Mg-base alloy with Al+Y powder

    Institute of Scientific and Technical Information of China (English)

    陈长军; 王东生; 王茂才

    2004-01-01

    The surface properties of ZM5 Mg-base alloy were modified by laser cladding with Al+ Y powder. Laser cladding was carried out with a 5 kW continuous wave CO2 laser by melting the preplaced powder mixture of Al and Y. Following laser cladding, the cladding zone was characterized by a detailed microstructural observation and phase analysis. Moreover, the microhardness and element distribution were evaluated in detail. The surface modified layer consists of Mg17 Al12 and Al4 MgY phases, while a-Mg and Mg17 Al12 in the substrate. The microhardness of the cladding zone was significantly enhanced as high as HV122 - 180 as compared to HV60 - 80 of the substrate region. The maximal hardness about HV224 is in the interface due to the formation of intermetallic Mg17 Al12 phase. The microstructure is refined and Mg diffuses into the cladding material which leads to the formation of Mg17 Al12.

  12. Modelling of laser cladding of magnesium alloys with pre-placed powders

    Science.gov (United States)

    Guo, Li-Feng

    As a surface engineering technique, high-power laser cladding, has shown great potential for improving the corrosion resistance of magnesium alloys. Its main advantage over other processes, is its ability to form relatively thick protective coatings on selected areas where improved properties are desired. It is also a 'clean' process. However, previous research studies have found that in laser cladding of magnesium alloys, the problem of a high degree of dilution cannot be easily overcome. Moreover, in-depth studies using analytical or numerical modelling can rarely be found in the literature for addressing laser cladding with pre-placed powders with the aim of predicting the level of dilution. In the first phase of this study, a simplified thermal model based on the finite element method (FEM) was developed to study the phenomenon of dilution in laser cladding of a magnesium alloy. In the model, the powder bed was treated as a continuum, and a high power continuous wave (CW) laser was employed. The results of the simulations of the FEM model together with those of the statistical analyses showed that although, under normal cladding conditions, a process window can be established for achieving good interfacial bonding between the substrate and the clad coating, a low dilution level was extremely difficult to achieve. This was primarily attributed to the low melting point and the high thermal diffusivity of magnesium as well as the relatively long laser-material interaction time. To overcome the dilution problem, the double-layer cladding technique was explored, and was found to be able to produce low dilution clads with improved corrosion resistance. In considering the improvement of corrosion resistance that can be caused by laser surface modification to magnesium alloys, a comparison was made between the techniques of laser surface melting and laser cladding. The results of the potentiodynamic polarisation tests showed that the improvement obtained from laser

  13. Microstructure and Fractural Morphology of Cobalt-based Alloy Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    CHEN Hao; PAN Chun-xu

    2003-01-01

    The solidification features,micro-segregation,and fracture characteristics of cobalt-based alloy on the substrate of 20CrMo steel by laser cladding were studied by using electron microscopy.Experimental results show that the fine columnar grains and cellular dendrite grains are obtained which are perpendicular to the coating/substrate interface;the primary arms are straight while the side branches are degenerated;the microstructure consists of primary face-centered cubic (fcc) Co dendrites and a network of Cr-enriched eutectic M23C6 (M=Cr,W,Fe) carbides;the micro-segregation is severe for the rapid heating and cooling of laser cladding;the typical brittle intergranular fracture occurs in cobalt-based laser cladding layer.

  14. Microstructural characterization of rapidly solidified Al-Li-Co powders

    Science.gov (United States)

    Samuel, Fawzy H.

    1986-01-01

    A study of the combined effect of alloying elements and melt superheat has been carried out on the as-solidified structure of rapidly solidified Al-Li-Co powders. Three alloys, viz., Al-3 pct Li, Al-3 pct Li-0.4 pct Co, and Al-3 pct Li-0.8 pct Co were chosen, and the liquid melt in each alloy atomized from the temperatures 1173 and 1073 K, using the centrifugal atomization technique. The microstructural characterization was done using light, scanning, and transmission electron microscopy. Four types of microstructures, viz., dendritic, cellular, equiaxed-type, and featureless structures, were observed by light microscopy. The cooling rate, as determined from the same, lay in the range 104 to 106 Ks-1, but was seen to go beyond 107 Ks-1 when estimated from TEM micrographs. On the micro-level, the Al-Li powders were found to exhibit dendritic structures with differing morphologies, whereas low-angle cell walls with perturbed interfaces were the main structural features observed in the Al-Li-Co alloys. Increasing both cobalt content and powder particle diameter favored transition from dendritic into cellular structure. The featureless zone was comprised mainly of elongated columnar grains (0.2 μm width and 1.5 μm length). A mechanism describing the cellular structure formation has been proposed. Aging of the melt-quenched powders at 473 K for times up to 100 hours results in the dissolution of the cellular structure. A mechanism for the same has been postulated. The difference in the superheats chosen in the present work is found not sufficient to cause drastic microstructural changes.

  15. Built-up Al-Li structures for cryogenic tank and dry bay applications

    Science.gov (United States)

    Lisagor, W. Barry

    1993-02-01

    The objectives are: (1) to demonstrate the cost benefits of built-up cryotank and dry bay structures; (2) to study of benefits of using Al alloys; (3) to study of benefit of using Al-Li alloys; (4) to evaluate alternative low-cost stiffener and joining concepts.

  16. Built-up Al-Li structures for cryogenic tank and dry bay applications

    Science.gov (United States)

    Lisagor, W. Barry

    1993-01-01

    The objectives are: (1) to demonstrate the cost benefits of built-up cryotank and dry bay structures; (2) to study of benefits of using Al alloys; (3) to study of benefit of using Al-Li alloys; (4) to evaluate alternative low-cost stiffener and joining concepts.

  17. White Paper Summary of 2nd ASTM International Workshop on Hydrides in Zirconium Alloy Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Sindelar, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Louthan, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); PNNL, B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-29

    This white paper recommends that ASTM International develop standards to address the potential impact of hydrides on the long term performance of irradiated zirconium alloys. The need for such standards was apparent during the 2nd ASTM International Workshop on Hydrides in Zirconium Alloy Cladding and Assembly Components, sponsored by ASTM International Committee C26.13 and held on June 10-12, 2014, in Jackson, Wyoming. The potentially adverse impacts of hydrogen and hydrides on the long term performance of irradiated zirconium-alloy cladding on used fuel were shown to depend on multiple factors such as alloy chemistry and processing, irradiation and post irradiation history, residual and applied stresses and stress states, and the service environment. These factors determine the hydrogen content and hydride morphology in the alloy, which, in turn, influence the response of the alloy to the thermo-mechanical conditions imposed (and anticipated) during storage, transport and disposal of used nuclear fuel. Workshop presentations and discussions showed that although hydrogen/hydride induced degradation of zirconium alloys may be of concern, the potential for occurrence and the extent of anticipated degradation vary throughout the nuclear industry because of the variations in hydrogen content, hydride morphology, alloy chemistry and irradiation conditions. The tools and techniques used to characterize hydrides and hydride morphologies and their impacts on material performance also vary. Such variations make site-to-site comparisons of test results and observations difficult. There is no consensus that a single material or system characteristic (e.g., reactor type, burnup, hydrogen content, end-of life stress, alloy type, drying temperature, etc.) is an effective predictor of material response during long term storage or of performance after long term storage. Multi-variable correlations made for one alloy may not represent the behavior of another alloy exposed to

  18. Wear Characteristics of Ni-Based Hardfacing Alloy Deposited on Stainless Steel Substrate by Laser Cladding

    Science.gov (United States)

    Awasthi, Reena; Limaye, P. K.; Kumar, Santosh; Kushwaha, Ram P.; Viswanadham, C. S.; Srivastava, Dinesh; Soni, N. L.; Patel, R. J.; Dey, G. K.

    2015-03-01

    In this study, dry sliding wear characteristics of the Ni-based hardfacing alloy (Ni-Mo-Cr-Si) deposited on stainless steel SS316L substrate by laser cladding have been presented. Dry sliding wear behavior of the laser clad layer was evaluated against two different counter bodies, AISI 52100 chromium steel (~850 VHN) and tungsten carbide ball (~2200 VHN) to study both adhesive and abrasive wear characteristics, in comparison with the substrate SS316L using ball on plate reciprocating wear tester. The wear resistance was evaluated as a function of load and sliding speed for a constant sliding amplitude and sliding distance. The wear mechanisms were studied on the basis of wear surface morphology and microchemical analysis of the wear track using SEM-EDS. Laser clad layer of Ni-Mo-Cr-Si on SS316L exhibited much higher hardness (~700 VHN) than that of substrate SS316L (~200 VHN). The laser clad layer exhibited higher wear resistance as compared to SS316L substrate while sliding against both the counterparts. However, the improvement in the wear resistance of the clad layer as compared to the substrate was much higher while sliding against AISI 52100 chromium steel than that while sliding against WC, at the same contact stress intensity.

  19. Cold Spray Coating Technique with FeCrAl Alloy Powder for Developing Accident Tolerant Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dong Jun; Kim, Hyun Gil; Park, Jeong Yong; Jung, Yang Il; Park, Jung Hwan; Koo, Yang Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Various approaches to enhance safety have been suggested, replacing current Zr-based alloys for fuel cladding with advanced materials exhibiting lower oxidation rates can be a basic solution. Many advanced materials such as FeCrAl alloys; Mn+1AXn, (MAX) phases, where n = 1 to 3, M is an early transition metal, A is an A-group (mostly IIIA and IVA, or groups 13 and 14) element and X is either carbon or nitrogen; Mo; and SiC are being considered as possible candidates. Among the proposed fuel cladding substitutes, Fe-based alloys are one of the most promising candidates owing to their excellent formability, high strength, and oxidation resistance at high temperature. In this work, the ATF technology concept of Fe-based alloy coating on the existing Zr-alloy cladding was considered and results on the optimization study for fabrication of coated tube samples were described. Result obtained from high temperature oxidation test under steam environment at 1200 .deg. C indicates that FeCrAl alloy coated Zr metal matrix may maintain its integrity during LOCA. This means that accident tolerance of FeCrAl alloy coated Zr cladding sample had been greatly improved compared to that of existing Zr-based alloy fuel cladding.

  20. Laser multi-layer cladding on ZM6 magnesium base alloy

    Institute of Scientific and Technical Information of China (English)

    Changjun Chen(陈长军); Dongsheng Wang(王东生); Maocai Wang(王茂才)

    2003-01-01

    A pulsed Nd: YAG laser is used in multi-layer cladding on ZM6 Mg base alloys. The microstructure isstudied with an optical microscope and a scanning electron microscope (SEM). The composition within thelayer was determined by electron probe microanalysis (EPMA). X-ray diffraction (XRD) was also used toinvestigate the phase of constitutes of the cladding zone. The results show that microstructure in solidifiedcladding layer changes much when treated by high energy laser beam. The microstructure of the ZM6alloy consists of α-Mg and Mg9Nd, while the L-ZM6 of α-Mg, Mg9Nd and c-Zr. The depth of the claddingis over 1 mm. Many fine particles were found to be distributed homogeneously throughout the matrix andthe columnar grain grows along substrate.

  1. XRD and TEM analysis of the microstructure in the brazing joint of 3003 cladding aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Tao Feng; Songnian Lou; Luhai Wu; Yajiang Li

    2005-01-01

    The material used in this experiment was 3003 cladding aluminum alloy, the cladding metal was 4004 aluminum alloy.The aluminum plate was brazed by means of vacuum brazing. The microstructure in the brazing joint was studied by means of X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The test result indicates that the suitable brazing technique parameters are brazing temperature, 628℃; keeping time, 10 min; vacuum degree, 6.5×10-4 Pa. XRD test indicates that there are new intermetallic compounds different from the base metal. TEM analysis indicates that Cu2Mg and Cu3Mn2Mg are formed in the brazing joint. The shape of Cu2Mg is irregular and the shape of Cu3Mn2Mg is circle, and there are tiny particles in it.

  2. Laser cladding of a Mg based Mg-Gd-Y-Zr alloy with Al-Si powders

    Science.gov (United States)

    Chen, Erlei; Zhang, Kemin; Zou, Jianxin

    2016-03-01

    In the present work, a Mg based Mg-Gd-Y-Zr alloy was subjected to laser cladding with Al-Si powders at different laser scanning speeds in order to improve its surface properties. It is observed that the laser clad layer mainly contains Mg2Si, Mg17Al12 and Al2(Gd,Y) phases distributed in the Mg matrix. The depth of the laser clad layer increases with decreasing the scanning speed. The clad layer has graded microstructures and compositions. Both the volume fraction and size of Mg2Si, Mg17Al12 and Al2(Gd,Y) phases decreases with the increasing depth. Due to the formation of these hardening phases, the hardness of clad layer reached a maximum value of HV440 when the laser scanning speed is 2 mm/s, more than 5 times of the substrate (HV75). Besides, the corrosion properties of the untreated and laser treated samples were all measured in a NaCl (3.5 wt.%) aqueous solution. The corrosion potential was increased from -1.77 V for the untreated alloy to -1.13 V for the laser clad alloy with scanning rate of 2 mm/s, while the corrosion current density was reduced from 2.10 × 10-5 A cm-2 to 1.64 × 10-6 A cm-2. The results show that laser cladding is an efficient method to improve surface properties of Mg-Rare earth alloys.

  3. High speed laser cladding: solidification conditions and microstructure of a cobalt-based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Frenk, A. (Dept. of Materials, Swiss Federal Inst. of Tech., Lausanne (Switzerland)); Kurz, W. (Dept. of Materials, Swiss Federal Inst. of Tech., Lausanne (Switzerland))

    1993-12-20

    Laser cladding experiments with a hypoeutectic Stellite 6 alloy have been performed with scanning speeds ranging from conventional values (1.67 mm s[sup -1]) up to very fast values (167 mm s[sup -1]). The evolution of the secondary dendrite arm spacing is discussed using the solidification conditions deduced from a two-dimensional heat flux model and the quaternary Co-Cr-C-W phase diagram. (orig.)

  4. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Krawchuk, M.T.; Van Weele, S.F. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1995-08-01

    A number of developmental and commercial tubing alloys and claddings have previously been exposed in Phase I to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. This program is exposing samples of TP 347, RA-85H, HR-3C, 253MA, Fe{sub 3}Al + 5Cr, 310 modified, NF-709, 690 clad, and 671 clad, which showed good corrosion resistance from Phase 1, to the actual operating conditions of a 250-MW, coal-fired boiler. The samples were installed on air-cooled, retractable corrosion probes, installed in the reheater cavity, and are being controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. The exposure will continue for 4000, 12,000, and 16,000 hours of operation. After the three exposure times, the samples will be metallurgically examined to determine the wastage rates and mode of attack. The probes were commissioned November 16, 1994. The temperatures are being recorded every 15 minutes, and the weighted average temperature calculated for each sample. Each of the alloys is being exposed to a temperature in each of two temperature bands-1150 to 1260{degrees}F and 1260 to 1325{degrees}F. After 2000 hours of exposure, one of the corrosion probes was cleaned and the wall thicknesses were ultrasonically measured. The alloy performance from the field probes will be discussed.

  5. Influence of Zirconia on Hydroxyapatite Coating on Ti-Alloy by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    杜海燕; 霍伟荣; 高海; 王丽娟; 邱世鹏; 刘家臣

    2003-01-01

    Coating titanium alloy with the bioceramic material hydroxyapatite(HAP) has been used to improve the poor osteoinductive properties of pure titanium alloy. But in clinical applications, the mechanical failure of HAP-coated titanium alloy implant suffered at the interface of the HAP coatings and titanium alloy substrate will be a potential weakness in prosthesis. Yttria-stablized zirconia (YSZ) is expected to enhance the mechanical properties of the HAP coating and reduce the coefficient of thermal expansion difference between the coated layer and the substrate. These may reinforce the bonding strength between the coatings and the substrate. In this paper, HAP/YSZ composite coatings were cladded by laser. The effects of zirconia on the microstructure, mechanical properties and formation of tricalcium phosphate (TCP, Ca3(PO4)2) of the HAP/YSZ composite coatings were evaluated. XRD, SEM and TEM were used to investigate the phase composition, microstructure and morphology of the coatings. The experimental results showed that adding YSZ in coatings was favorable to the composition and stability of HAP, and to the improvement of the adhesion strength, microhardness and microtoughness. A well uniform, crack-free coating of HAP/YSZ composites was formed on Ti-alloy substrate by laser cladding.

  6. Development of ODS FeCrAl alloys for accident-tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-18

    FeCrAl alloys are prime candidates for accident-tolerant fuel cladding due to their excellent oxidation resistance up to 1400 C and good mechanical properties at intermediate temperature. Former commercial oxide dispersion strengthened (ODS) FeCrAl alloys such as PM2000 exhibit significantly better tensile strength than wrought FeCrAl alloys, which would alloy for the fabrication of a very thin (~250 m) ODS FeCrAl cladding and limit the neutronic penalty from the replacement of Zr-based alloys by Fe-based alloys. Several Fe-12-Cr-5Al ODS alloys where therefore fabricated by ball milling FeCrAl powders with Y2O3 and additional oxides such as TiO2 or ZrO2. The new Fe-12Cr-5Al ODS alloys showed excellent tensile strength up to 800 C but limited ductility. Good oxidation resistance in steam at 1200 and 1400 C was observed except for one ODS FeCrAl alloy containing Ti. Rolling trials were conducted at 300, 600 C and 800 C to simulate the fabrication of thin tube cladding and a plate thickness of ~0.6mm was reached before the formation of multiple edge cracks. Hardness measurements at different stages of the rolling process, before and after annealing for 1h at 1000 C, showed that a thinner plate thickness could likely be achieved by using a multi-step approach combining warm rolling and high temperature annealing. Finally, new Fe-10-12Cr-5.5-6Al-Z gas atomized powders have been purchased to fabricate the second generation of low-Cr ODS FeCrAl alloys. The main goals are to assess the effect of O, C, N and Zr contents on the ODS FeCrAl microstructure and mechanical properties, and to optimize the fabrication process to improve the ductility of the 2nd gen ODS FeCrAl while maintaining good mechanical strength and oxidation resistance.

  7. Microstructure and abrasion wear behavior of Ni-based laser cladding alloy layer at high temperature

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; LIU Su-qin; WANG Shun-xing

    2005-01-01

    Ni-based alloy coating on 21-4-N heat-resistant steel was prepared using CO2 laser, and the high-temperature abrasion wear was tested. The microstructure of this cladding layer and its abrasion wear behavior at high temperature by changing compositions and temperatures were investigated by means of optical microscope and scanning electron microscope. Among the three compositions of cladding layer, i.e. Ni21+20%WC+0.5%CeO2, Ni25+20%WC+0.5%CeO2 and Ni60+20%WC+0.5%CeO2, the experimental results show that Ni21+20%WC+0.5%CeO2 cladding layer is made up of finer grains, and presents the best abrasion wear behavior at high temperature. The wear pattern of laser cladding layer is mainly grain abrasion at lower temperature, and it would be changed to adhesive abrasion and oxide abrasion at higher temperature.

  8. Microstructure and Wear Resistance of Laser Clad Cobalt-Based Alloy/SiCp Composite Coating

    Institute of Scientific and Technical Information of China (English)

    LI Ming-xi; SI Song-hua; HE Yi-zhu; SUN Guo-xiong

    2004-01-01

    The SiCp (20 %) reinforced cobalt-based alloy composite coatings deposited by laser cladding on IF steel were introduced. The microstructure across the whole section of such coatings was examined using optical microscope, scanning electron microscope (SEM) and X-ray diffractometer (XRD), and the wear resistance of the coatings was measured by MM-200 type wear testing machine. The results show that the SiCp is completely dissolved during laser cladding and the primary phase in the coatings is γ-Co. The other phases, such as Si2W, CoWSi, Cr3Si and CoSi2, are formed by carbon, silicon reacting with other elements existing in the melting pool. There are various crystallization morphologies in different zones, such as planar crystallization at the interface, followed by cellular and dendrite crystallization from interface to the surface. The direction of solidification changes from one direction perpendicular to interface to multi-directions at the central and upper regions of the clad. The wear resistance of the clad is improved by adding SiCp.

  9. Ferritic Alloys as Accident Tolerant Fuel Cladding Material for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, Raul B. [General Electric Global Research, Schnectady, NY (United States)

    2014-12-30

    The objective of the GE project is to demonstrate that advanced steels such as iron-chromium-aluminum (FeCrAl) alloys could be used as accident tolerant fuel cladding material in commercial light water reactors. The GE project does not include fuel development. Current findings support the concept that a FeCrAl alloy could be used for the cladding of commercial nuclear fuel. The use of this alloy will benefit the public since it is going to make the power generating light water reactors safer. In the Phase 1A of this cost shared project, GE (GRC + GNF) teamed with the University of Michigan, Los Alamos National Laboratory, Brookhaven National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory to study the environmental and mechanical behavior of more than eight candidate cladding materials both under normal operation conditions of commercial nuclear reactors and under accident conditions in superheated steam (loss of coolant condition). The main findings are as follows: (1) Under normal operation conditions the candidate alloys (e.g. APMT, Alloy 33) showed excellent resistance to general corrosion, shadow corrosion and to environmentally assisted cracking. APMT also showed resistance to proton irradiation up to 5 dpa. (2) Under accident conditions the selected candidate materials showed several orders of magnitude improvement in the reaction with superheated steam as compared with the current zirconium based alloys. (3) Tube fabrication feasibility studies of FeCrAl alloys are underway. The aim is to obtain a wall thickness that is below 400 µm. (4) A strategy is outlined for the regulatory path approval and for the insertion of a lead fuel assembly in a commercial reactor by 2022. (5) The GE team worked closely with INL to have four rodlets tested in the ATR. GE provided the raw stock for the alloys, the fuel for the rodlets and the cost for fabrication/welding of the rodlets. INL fabricated the rodlets and the caps and welded them to

  10. Ferritic Alloys as Accident Tolerant Fuel Cladding Material for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, Raul B. [General Electric Global Research, Schnectady, NY (United States)

    2014-09-30

    The objective of the GE project is to demonstrate that advanced steels such as iron-chromium-aluminum (FeCrAl) alloys could be used as accident tolerant fuel cladding material in commercial light water reactors. The GE project does not include fuel development. Current findings support the concept that a FeCrAl alloy could be used for the cladding of commercial nuclear fuel. The use of this alloy will benefit the public since it is going to make the power generating light water reactors safer. In the Phase 1A of this cost shared project, GE (GRC + GNF) teamed with the University of Michigan, Los Alamos National Laboratory, Brookhaven National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory to study the environmental and mechanical behavior of more than eight candidate cladding materials both under normal operation conditions of commercial nuclear reactors and under accident conditions in superheated steam (loss of coolant condition). The main findings are as follows: (1) Under normal operation conditions the candidate alloys (e.g. APMT, Alloy 33) showed excellent resistance to general corrosion, shadow corrosion and to environmentally assisted cracking. APMT also showed resistance to proton irradiation up to 5 dpa. (2) Under accident conditions the selected candidate materials showed several orders of magnitude improvement in the reaction with superheated steam as compared with the current zirconium based alloys. (3) Tube fabrication feasibility studies of FeCrAl alloys are underway. The aim is to obtain a wall thickness that is below 400 µm. (4) A strategy is outlined for the regulatory path approval and for the insertion of a lead fuel assembly in a commercial reactor by 2022. (5) The GE team worked closely with INL to have four rodlets tested in the ATR. GE provided the raw stock for the alloys, the fuel for the rodlets and the cost for fabrication/welding of the rodlets. INL fabricated the rodlets and the caps and welded them to

  11. Advanced ODS FeCrAl alloys for accident-tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N [ORNL; Unocic, Kinga A [ORNL; Hoelzer, David T [ORNL; Pint, Bruce A [ORNL

    2014-09-01

    ODS FeCrAl alloys are being developed with optimum composition and properties for accident tolerant fuel cladding. Two oxide dispersion strengthened (ODS) Fe-15Cr-5Al+Y2O3 alloys were fabricated by ball milling and extrusion of gas atomized metallic powder mixed with Y2O3 powder. To assess the impact of Mo on the alloy mechanical properties, one alloy contained 1%Mo. The hardness and tensile properties of the two alloys were close and higher than the values reported for fine grain PM2000 alloy. This is likely due to the combination of a very fine grain structure and the presence of nano oxide precipitates. The nano oxide dispersion was however not sufficient to prevent grain boundary sliding at 800 C and the creep properties of the alloys were similar or only slightly superior to fine grain PM2000 alloy. Both alloys formed a protective alumina scale at 1200 C in air and steam and the mass gain curves were similar to curves generated with 12Cr-5Al+Y2O3 (+Hf or Zr) ODS alloys fabricated for a different project. To estimate the maximum temperature limit of use for the two alloys in steam, ramp tests at a rate of 5 C/min were carried out in steam. Like other ODS alloys, the two alloys showed a significant increase of the mas gains at T~ 1380 C compared with ~1480 C for wrought alloys of similar composition. The beneficial effect of Yttrium for wrought FeCrAl does not seem effective for most ODS FeCrAl alloys. Characterization of the hardness of annealed specimens revealed that the microstructure of the two alloys was not stable above 1000 C. Concurrent radiation results suggested that Cr levels <15wt% are desirable and the creep and oxidation results from the 12Cr ODS alloys indicate that a lower Cr, high strength ODS alloy with a higher maximum use temperature could be achieved.

  12. Laser cladding of tungsten carbides (Spherotene ®) hardfacing alloys for the mining and mineral industry

    Science.gov (United States)

    Amado, J. M.; Tobar, M. J.; Alvarez, J. C.; Lamas, J.; Yáñez, A.

    2009-03-01

    The abrasive nature of the mechanical processes involved in mining and mineral industry often causes significant wear to the associated equipment and derives non-negligible economic costs. One of the possible strategies to improve the wear resistance of the various components is the deposition of hardfacing layers on the bulk parts. The use of high power lasers for hardfacing (laser cladding) has attracted a great attention in the last decade as an alternative to other more standard methods (arc welding, oxy-fuel gas welding, thermal spraying). In laser cladding the hardfacing material is used in powder form. For high hardness applications Ni-, Co- or Fe-based alloys containing hard phase carbides at different ratios are commonly used. Tungsten carbides (WC) can provide coating hardness well above 1000 HV (Vickers). In this respect, commercially available WC powders normally contain spherical micro-particles consisting of crushed WC agglomerates. Some years ago, Spherotene ® powders consisting of spherical-fused monocrystaline WC particles, being extremely hard, between 1800 and 3000 HV, were patented. Very recently, mixtures of Ni-based alloy with Spherotene powders optimized for laser processing were presented (Technolase ®). These mixtures have been used in our study. Laser cladding tests with these powders were performed on low carbon steel (C25) substrates, and results in terms of microstructure and hardness will be discussed.

  13. Laser cladding of tungsten carbides (Spherotene) hardfacing alloys for the mining and mineral industry

    Energy Technology Data Exchange (ETDEWEB)

    Amado, J.M. [Departamento de Ingenieria Industrial II, Universidade da Coruna, Mendizabal s/n, Ferrol E-15403 (Spain); Tobar, M.J. [Departamento de Ingenieria Industrial II, Universidade da Coruna, Mendizabal s/n, Ferrol E-15403 (Spain)], E-mail: cote@udc.es; Alvarez, J.C.; Lamas, J.; Yanez, A. [Departamento de Ingenieria Industrial II, Universidade da Coruna, Mendizabal s/n, Ferrol E-15403 (Spain)

    2009-03-01

    The abrasive nature of the mechanical processes involved in mining and mineral industry often causes significant wear to the associated equipment and derives non-negligible economic costs. One of the possible strategies to improve the wear resistance of the various components is the deposition of hardfacing layers on the bulk parts. The use of high power lasers for hardfacing (laser cladding) has attracted a great attention in the last decade as an alternative to other more standard methods (arc welding, oxy-fuel gas welding, thermal spraying). In laser cladding the hardfacing material is used in powder form. For high hardness applications Ni-, Co- or Fe-based alloys containing hard phase carbides at different ratios are commonly used. Tungsten carbides (WC) can provide coating hardness well above 1000 HV (Vickers). In this respect, commercially available WC powders normally contain spherical micro-particles consisting of crushed WC agglomerates. Some years ago, Spherotene powders consisting of spherical-fused monocrystaline WC particles, being extremely hard, between 1800 and 3000 HV, were patented. Very recently, mixtures of Ni-based alloy with Spherotene powders optimized for laser processing were presented (Technolase). These mixtures have been used in our study. Laser cladding tests with these powders were performed on low carbon steel (C25) substrates, and results in terms of microstructure and hardness will be discussed.

  14. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings -- Phase 2 field testing

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Seitz, W.W.; Girshik, A. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1998-06-01

    In Phase 1 of this project, laboratory experiments were performed on a variety of developmental and commercial tubing alloys and claddings by exposing them to fireside corrosion tests which simulated a superheater or reheater in a coal-fired boiler. Phase 2 (in situ testing) has exposed samples of 347, RA85H, HR3C, RA253MA, Fe{sub 3}Al + 5Cr, Ta-modified 310, NF 709, 690 clad, 671 clad, and 800HT for up to approximately 16,000 hours to the actual operating conditions of a 250-MW, coal-fired boiler. The samples were installed on air-cooled, retractable corrosion probes, installed in the reheater cavity, and controlled to the operating metal temperatures of an existing and advanced-cycle, coal-fired boiler. Samples of each alloy were exposed for 4,483, 11,348, and 15,883 hours of operation. The present results are for the metallurgical examination of the corrosion probe samples after the full 15,883 hours of exposure. A previous topical report has been issued for the 4,483 hours of exposure.

  15. Amorphous Structures in Laser Cladding of ZL111 Aluminum Alloy:Semi-quantitative Study by Differential Thermal Analysis (DTA)

    Institute of Scientific and Technical Information of China (English)

    LI Xianqin; CHENG Zhaogu; XIA Jin'an; XU Guoliang; LIANG Gongying

    2000-01-01

    This paper deals with amorphous structures in the laser cladding. ZL111 alloy is the substrate and Ni-Cr-Al alloy is sprayed on the substrate as the coating material. The coating is clad by a 5 kW transverse flow CO2 laser. The observation of SEM and TEM reveal that in the laser cladding there are amorphous structures of two different morphologies: one is space curved flake-like, and exists in the white web-like structures; the other is fir leaf-like, and exists in the grain-like structures. Differential thermal analysis (DTA) is used to semi-quantitatively determine the content of the amorphous structures. A relation is obtained between the content of amorphous structures and the dimensionless laser cladding parameter C. We also show the changes of the amorphous structures after annealing.

  16. ODS Ferritic/martensitic alloys for Sodium Fast Reactor fuel pin cladding

    Science.gov (United States)

    Dubuisson, Philippe; Carlan, Yann de; Garat, Véronique; Blat, Martine

    2012-09-01

    The development of ODS materials for the cladding for Sodium Fast Reactors is a key issue to achieve the objectives required for the GEN IV reactors. CEA, AREVA and EDF have launched in 2007 an important program to determine the optimal fabrication parameters, and to measure and understand the microstructure and properties before, under and after irradiation of such cladding materials. The aim of this paper is to present the French program and the major results obtained recently at CEA on Fe-9/14/18Cr1WTiY2O3 ferritic/martensitic ODS materials. The first step of the program was to consolidate Fe-9/14/18Cr ODS materials as plates and bars to study the microstructure and the mechanical properties of the new alloys. The second step consists in producing tubes at a geometry representative of the cladding of new Sodium Fast Reactors. The optimization of the fabrication route at the laboratory scale is conducted and different tubes were produced. Their microstructure depends on the martensitic (Fe-9Cr) or ferritic (Fe-14Cr) structure. To join the plug to the tube, the reference process is the welding resistance. A specific approach is developed to model the process and support the development of the welds performed within the "SOPRANO" facility. The development at CEA of Fe-9/14/18Cr new ODS materials for the cladding for GENIV Sodium Fast Reactors is in progress. The first microstructural and mechanical characterizations are very encouraging and the full assessment and qualification of this new alloys and products will pass through the irradiation of specimens, tubes, fuel pins and subassemblies up to high doses.

  17. Optimization of pulsed TIG cladding process of stellite alloy on carbon steel using RSM

    Energy Technology Data Exchange (ETDEWEB)

    Madadi, F., E-mail: f.madadi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of); Ashrafizadeh, F. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of); Shamanian, M., E-mail: shamanian@cc.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of)

    2012-01-05

    Highlights: > This study is useful to optimize the welding process variables in order to control the heat input and cooling rates such that the hardness and dilution of the clad could be estimated. > Central composite rotatable design technique with five-level, four-factor full-factorial design matrix and mathematical models was used to predict hardness and dilution of pulsed gas tungsten arc weld cladding of stellite6 on carbon steel with high accuracy. > The welding current is an effective parameter affecting heat input and melting. In this regard, it is the most important process parameter which influences the dilution. Increase welding current leads to increase in dilution percentage and vice versa. The effect of percentage on time is less important when compared to the other factors. > The results predicted by mathematical models were close to those obtained by experiments. The confirmation tests also indicated high correlation between the mentioned values. > All of the chosen pulse GTAW parameters were significant and showed a noticeable influence on clad dilution. - Abstract: Stellite 6 is a cobalt-base alloy which is resistant to wear and corrosion and retains these properties at high temperatures. The exceptional wear resistance of Stellite 6 is mainly due to the unique inherent characteristics of the hard carbides dispersed in a Co-Cr alloy matrix. In this study, pulsed tungsten inert gas (TIG) cladding process was carried out to deposit Stellite 6 on plain carbon steel plate. The beneficial effects of this cladding process are low heat input, low distortion, controlled weld bead volume, less hot cracking tendency, less absorption of gases by weld pool and better control of the fusion zone. The dilution effect is a key issue in the quality of cladded layers and, in this regard, the pulsed current tungsten inert gas (PCTIG) was performed to decrease excess heat input and melting of substrate. This paper deals with the investigation of the hardness and

  18. Microstructure and Wear Behavior of CoCrFeMnNbNi High-Entropy Alloy Coating by TIG Cladding

    Directory of Open Access Journals (Sweden)

    Wen-yi Huo

    2015-01-01

    Full Text Available Alloy cladding coatings are widely prepared on the surface of tools and machines. High-entropy alloys are potential replacements of nickel-, iron-, and cobalt-base alloys in machining due to their excellent strength and toughness. In this work, CoCrFeMnNbNi HEA coating was produced on AISI 304 steel by tungsten inert gas cladding. The microstructure and wear behavior of the cladding coating were studied by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometer, microhardness tester, pin-on-ring wear tester, and 3D confocal laser scanning microscope. The microstructure showed up as a nanoscale lamellar structure matrix which is a face-centered-cubic solid solution and niobium-rich Laves phase. The microhardness of the cladding coating is greater than the structure. The cladding coating has excellent wear resistance under the condition of dry sliding wear, and the microploughing in the worn cladding coating is shallower and finer than the worn structure, which is related to composition changes caused by forming the nanoscale lamellar structure of Laves phase.

  19. Regularities of crystallographic texture formation in cladding tubes from Zr-based alloys during their production

    Science.gov (United States)

    Isaenkova, M.; Perlovich, Yu; Fesenko, V.

    2016-04-01

    This paper summarizes researches of the authors, which are directed on the development of the methodological basis of X-ray studies in the materials science of zirconium and on the systematization of new experimental results obtained using developed methods. The paper describes regularities of the formation of the crystallographic texture and the substructure inhomogeneity of cladding tubes from zirconium alloys at various stages of their manufacturing, i.e. during hot and cold deformation, recrystallization, phase transformations and interactions of the above processes.

  20. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings -- Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Seitz, W.W. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1997-12-01

    In Phase 1 a variety of developmental and commercial tubing alloys and claddings were exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase 2 (in situ testing) has exposed samples of 347 RA-85H, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 Ta modified, NF 709, 690 clad, and 671 clad for approximately 4,000, 12,000, and 16,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were assembled on an air-cooled, retractable corrosion probe, the probe was installed in the reheater activity of the boiler and controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. The results will be presented for the preliminary metallurgical examination of the corrosion probe samples after 16,000 hours of exposure. Continued metallurgical and interpretive analysis is still on going.

  1. Laser cladding of a cobalt-based alloy: processing parameters and microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Frenk, A. (Swiss Federal Inst. of Technology, Lausanne (Switzerland). Dept. of Materials); Henchoz, N. (Swiss Federal Inst. of Technology, Lausanne (Switzerland). Dept. of Materials); Kurz, W. (Swiss Federal Inst. of Technology, Lausanne (Switzerland). Dept. of Materials)

    1993-12-01

    Laser cladding experiments with a hypoeutectic Stellite 6 alloy were carried out with a low (1.67 mm/s), an intermediate (13.3 mm/s) and a very high (167 mm/s) scanning speed in order to examine the influence of the processing conditions on the type, size and fraction of phases present. Altering the scanning speed over two orders of magnitude led to a marked decrease in the microstructural size. With the fast processing conditions, the fraction of interdendritic eutectic was also decreased. The results are discussed based on a recent dendritic growth model for multicomponent alloys, using the solidification conditions deduced from a two-dimensional (2D) heat flux model and the phase diagram parameters determined with numerical calculations of the quaternary Co-Cr-C-W phase diagram. (orig.)

  2. High-temperature steam oxidation kinetics of the E110G cladding alloy

    Science.gov (United States)

    Király, Márton; Kulacsy, Katalin; Hózer, Zoltán; Perez-Feró, Erzsébet; Novotny, Tamás

    2016-07-01

    In the course of recent years, several experiments were performed at MTA EK (Centre for Energy Research, Hungarian Academy of Sciences) on the isothermal high-temperature oxidation of the improved Russian cladding alloy E110G in steam/argon atmosphere. Using these data and designing additional supporting experiments, the oxidation kinetics of the E110G alloy was investigated in a wide temperature range, between 600 °C and 1200 °C. For short durations (below 500 s) or high temperatures (above 1065 °C) the oxidation kinetics was found to follow a square-root-of-time dependence, while for longer durations and in the intermediate temperature range (800-1000 °C) it was found to approach a cube-root-of-time dependence rather than a square-root one. Based on the results a new best-estimate and a conservative oxidation kinetics model were created.

  3. Fabrication of iron aluminum alloy/steel laminate by clad rolling

    Science.gov (United States)

    Masahashi, N.; Watanabe, S.; Hanada, S.; Komatsu, K.; Kimura, G.

    2006-05-01

    Laminates of an iron-aluminum alloy (20Al) and three types of steel—chromium molybdenum (CrMo), high carbon (FeCMn), and precipitation hardening steel with niobium carbide (FeCNb)—were fabricated at 600 °C and 1000 °C by clad rolling based on the compression stress ratio of 20Al to steel. The laminates fabricated at 600 °C exhibit a deformation microstructure with partial recrystallization, while those at 1000 °C reveal a refined microstructure. The 20Al layer of all the laminates exhibit a {001} texture, and the intensity of the texture increases with a decrease in the fabrication temperature and an increase in the reduction. The bending deformability of a laminate increases with a decrease in the compression stress ratio and by a reduction in the intensity of the {001} texture. The clad plate is further rolled at room temperature to a thickness of approximately 150 µm, which enables winding without damage. It is concluded that a high-strength steel at high temperatures and a high Al content in the Fe-Al alloy is beneficial for the fabrication of deformable laminates.

  4. Laser Cladding of an Al-11.7Wt% Si Alloy on ZM5 Magnesium Alloy to Enhance the Corrosion Resistance

    Institute of Scientific and Technical Information of China (English)

    CHENChang-jun; WANGMao-cai; WANGDong-sheng

    2004-01-01

    Magnesium alloy is an important engineering materials, but the wider application is restricted by poor corrosion resistance. An attempt was made to enhance the corrosion resistance and microhardness of a Mg-Al base ZM5 alloy by laser cladding of A1-11.7Wt%Si alloy powder with thickness 1.1 mm and 1.7inm. The microstructure, phase and corrosion properties were analyzed by scanning electron micrographic (SEM), electron probe microanalysis(EPMA), vicker hardness tester and corrosion measurement system, respectively. Microhardness of the cladding layer was enhanced to 150-375Hv as compared to 60-99Hv of the substrate. The corrosion potential (Ecorr) of the cladding sample was 80mv higher than the substrate, while the corrosion current (lcorr) was lower than the substrate.

  5. Laser Cladding of an Al-11.7Wt% Si Alloy on ZM5 Magnesium Alloy to Enhance the Corrosion Resistance

    Institute of Scientific and Technical Information of China (English)

    CHEN Chang-jun; WANG Mao-cai; WANG Dong-sheng

    2004-01-01

    Magnesium alloy is an important engineering materials, but the wider application is restricted by poor corrosion resistance. An attempt was made to enhance the corrosion resistance and microhardness of a Mg-Al base ZM5 alloy by laser cladding of Al-11.7Wt%Si alloy powder with thickness 1.1mm and 1.7mm. The microstructure, phase and corrosion properties were analyzed by scanning electron micrographic (SEM), electron probe microanalysis(EPMA), vicker hardness tester and corrosion measurement system, respectively. Microhardness of the cladding layer was enhanced to 150-375Hv as compared to 60-99Hv of the substrate. The corrosion potential (Ecorr) of the cladding sample was 80mv higher than the substrate, while the corrosion current (Icorr) was lower than the substrate.

  6. Optimization of N18 Zirconium Alloy for Fuel Cladding of Water Reactors

    Institute of Scientific and Technical Information of China (English)

    B.X. Zhou; M. Y. Yao; Z.K. Li; X.M. Wang; J. Zhoua; C.S. Long; Q. Liu; B.F. Luan

    2012-01-01

    In order to optimize the microstructure and composition of N18 zirconium alloy (Zr-1Sn-0.35Nb-0.35Fe-0.1Cr, in mass fraction, %), which was developed in China in 1990s, the effect of microstructure and composition variation on the corrosion resistance of the N18 alloy has been investigated. The autoclave corrosion tests were carried out in super heated steam at 400 ~C/10.3 MPa, in deionized water or lithiated water with 0.01 mol/L LiOH at 360 ~C/18.6 MPa. The exposure time lasted for 300-550 days according to the test temperature. The results show that the microstructure with a fine and uniform distribution of second phase particles (SPPs), and the decrease of Sn content from 1% (in mass fraction, the same as follows) to 0.8% are of benefit to improving the corrosion resistance; It is detrimental to the corrosion resistance if no Cr addition. The addition of Nb content with upper limit (0.35%) is beneficial to improving the corrosion resistance. The addition of Cu less than 0.1% shows no remarkable influence upon the corrosion resistance for N18 alloy. Comparing the corrosion resistance of the optimized N18 with other commercial zirconium alloys, such as Zircaloy-4, ZIRLO, E635 and Ell0, the former shows superior corrosion resistance in all autoclave testing conditions mentioned above. Although the data of the corrosion resistance as fuel cladding for high burn-up has not been obtained yet, it is believed that the optimized N18 alloy is promising for the candidate of fuel cladding materials as high burn-up fuel assemblies. Based on the theory that the microstructural evolution of oxide layer during corrosion process will affect the corrosion resistance of zirconium alloys, the improvement of corrosion resistance of the N18 alloy by obtaining the microstructure with nano-size and uniform distribution of SPPs, and by decreasing the content of Sn and maintaining the content of Cr is discussed.

  7. The Corrosion and Corrosion Fatigue Behavior of Nickel Based Alloy Weld Overlay and Coextruded Claddings

    Science.gov (United States)

    Stockdale, Andrew

    The use of low NOx boilers in coal fired power plants has resulted in sulfidizing corrosive conditions within the boilers and a reduction in the service lifetime of the waterwall tubes. As a solution to this problem, Ni-based weld overlays are used to provide the necessary corrosion resistance however; they are susceptible to corrosion fatigue. There are several metallurgical factors which give rise to corrosion fatigue that are associated with the localized melting and solidification of the weld overlay process. Coextruded coatings offer the potential for improved corrosion fatigue resistance since coextrusion is a solid state coating process. The corrosion and corrosion fatigue behavior of alloy 622 weld overlays and coextruded claddings was investigated using a Gleeble thermo-mechanical simulator retrofitted with a retort. The experiments were conducted at a constant temperature of 600°C using a simulated combustion gas of N2-10%CO-5%CO2-0.12%H 2S. An alternating stress profile was used with a minimum tensile stress of 0 MPa and a maximum tensile stress of 300 MPa (ten minute fatigue cycles). The results have demonstrated that the Gleeble can be used to successfully simulate the known corrosion fatigue cracking mechanism of Ni-based weld overlays in service. Multilayer corrosion scales developed on each of the claddings that consisted of inner and outer corrosion layers. The scales formed by the outward diffusion of cations and the inward diffusion of sulfur and oxygen anions. The corrosion fatigue behavior was influenced by the surface finish and the crack interactions. The initiation of a large number of corrosion fatigue cracks was not necessarily detrimental to the corrosion fatigue resistance. Finally, the as-received coextruded cladding exhibited the best corrosion fatigue resistance.

  8. Preparation and characterization of laser cladding wollastonite derived bioceramic coating on titanium alloy.

    Science.gov (United States)

    Li, Huan-cai; Wang, Dian-gang; Chen, Chuan-zhong; Weng, Fei; Shi, Hua

    2015-09-25

    The bioceramic coating is fabricated on titanium alloy (Ti6Al4V) by laser cladding the preplaced wollastonite (CaSiO3) powders. The coating on Ti6Al4V is characterized by x-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy, and attenuated total reflection Fourier-transform infrared. The interface bonding strength is measured using the stretching method using an RGD-5-type electronic tensile machine. The microhardness distribution of the cross-section is determined using an indentation test. The in vitro bioactivity of the coating on Ti6Al4V is evaluated using the in vitro simulated body fluid (SBF) immersion test. The microstructure of the laser cladding sample is affected by the process parameters. The coating surface is coarse, accidented, and microporous. The cross-section microstructure of the ceramic layer from the bottom to the top gradually changes from cellular crystal, fine cellular-dendrite structure to underdeveloped dendrite crystal. The coating on Ti6Al4V is composed of CaTiO3, CaO, α-Ca2SiO4, SiO2, and TiO2. After soaking in the SBF solution, the calcium phosphate layer is formed on the coating surface.

  9. Corrosion of the AlFeNi alloy used for the fuel cladding in the Jules Horowitz research reactor

    Science.gov (United States)

    Wintergerst, M.; Dacheux, N.; Datcharry, F.; Herms, E.; Kapusta, B.

    2009-09-01

    The AlFeNi aluminium alloy (1 wt% Fe, 1 wt% Ni, 1 wt% Mg) is expected to be used as nuclear fuel cladding for the Jules Horowitz experimental reactor. To guarantee a safe behaviour of the fuel, a good understanding of the fuel clad corrosion mechanisms is required. In this field, the experimental characterization of the selected alloy was performed. Then experimental studies of the aluminium alloy corrosion product obtained in autoclaves have shown an oxide film composed of two layers. This duplex structure results from a mixed growth mechanism: an anionic growth to develop the inner oxide and a cationic diffusion parallel to a dissolution-precipitation process to form the outer zone. Dynamic experiments at 70 °C have demonstrated that a solid diffusion step controls the release kinetic. Then post-irradiation exams performed on irradiated fuel plates were used to investigate the effects of the irradiation on the corrosion behaviour in the reactor core.

  10. Role of Laser Cladding Parameters in Composite Coating (Al-SiC) on Aluminum Alloy

    Science.gov (United States)

    Riquelme, Ainhoa; Escalera-Rodriguez, María Dolores; Rodrigo, Pilar; Rams, Joaquin

    2016-08-01

    The effect of the different control parameters on the laser cladding fabrication of Al/SiCp composite coatings on AA6082 aluminum alloy was analyzed. A high-power diode laser was used, and the laser control parameters were optimized to maximize the size (height and width) of the coating and the substrate-coating interface quality, as well as to minimize the melted zone depth. The Taguchi DOE method was applied using a L18 to reduce the number of experiments from 81 to only 18 experiments. Main effects, signal-noise ratio and analysis of variance were used to evaluate the effect of these parameters in the characteristics of the coating and to determine their optimum values. The influence of four control parameters was evaluated: (1) laser power, (2) scanning speed, (3) focal condition, and (4) powder feed ratio. Confirmation test with the optimal control parameters was carried out to evaluate the Taguchi method's effectivity.

  11. Comparative Study of Co-based Alloys in Repairing Low Cr-Mo steel Components by Laser Cladding

    Science.gov (United States)

    Díaz, E.; Amado, J. M.; Montero, J.; Tobar, M. J.; Yáñez, A.

    Refurbishment of damaged components is nowadays a useful solution to save maintenance costs. Laser cladding is one of the most advantageous solutions to fulfill this kind of repair. With the aim of reusing deteriorated steam circuit parts of thermal power stations, a laser cladding process has been developed. Different Co-based alloys of Stellite® and Tribaloy® families, which offer good resistance against impact, corrosion and erosive wear at high temperatures, were used as coating materials to improve the durability of this repair. A comparative study of morphology, structure and hardness of the deposited layers with optimized parameters has been carried out.

  12. Fiber laser cladding of nickel-based alloy on cast iron

    Science.gov (United States)

    Arias-González, F.; del Val, J.; Comesaña, R.; Penide, J.; Lusquiños, F.; Quintero, F.; Riveiro, A.; Boutinguiza, M.; Pou, J.

    2016-06-01

    Gray cast iron is a ferrous alloy characterized by a carbon-rich phase in form of lamellar graphite in an iron matrix while ductile cast iron presents a carbon-rich phase in form of spheroidal graphite. Graphite presents a higher laser beam absorption than iron matrix and its morphology has also a strong influence on thermal conductivity of the material. The laser cladding process of cast iron is complicated by its heterogeneous microstructure which generates non-homogeneous thermal fields. In this research work, a comparison between different types of cast iron substrates (with different graphite morphology) has been carried out to analyze its impact on the process results. A fiber laser was used to generate a NiCrBSi coating over flat substrates of gray cast iron (EN-GJL-250) and nodular cast iron (EN-GJS-400-15). The relationship between processing parameters (laser irradiance and scanning speed) and geometry of a single laser track was examined. Moreover, microstructure and composition were studied by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-Ray Diffraction (XRD). The hardness and elastic modulus were analyzed by means of micro- and nanoindentation. A hardfacing coating was generated by fiber laser cladding. Suitable processing parameters to generate the Ni-based alloy coating were determined. For the same processing parameters, gray cast iron samples present higher dilution than cast iron samples. The elastic modulus is similar for the coating and the substrate, while the Ni-based coating obtained presents a significantly superior hardness than cast iron.

  13. Microstructure and wear behavior of laser cladding Ni-based alloy composite coating reinforced by Ti(C,N) particulates

    Institute of Scientific and Technical Information of China (English)

    Qi Yongtian; Shi Hanchao; Zou Zengda; Hu Liping

    2008-01-01

    In this paper, Ni-based alloy composite coating reinforced by Ti (C,N) particles was fabricated on the mild steel through laser cladding technology. The microstructure of laser cladding layer was analyzed by means of optical microscopy (OM),X-ray diffraction (XRD) and scanning electron microscopy (SEM).The wear resistance test of the coating was evaluated using an M-2000 tester. The results showed that the Ni-based composite coating had an ability of rapid solidification to form dendritic crystals microstructure consisting of Ti (C,N) particulates uniformly distributed in the matrix. It was found that some Ti(C,N) particles are similar to be round in shape, and the others are irregular. Laser cladding layer reinforced by Ti(C,N) particulates was found to possess good wear resistance property.

  14. Carbide and nitride precipitation during laser cladding of Inconel 718 alloy coatings

    Science.gov (United States)

    Zhang, Yaocheng; Li, Zhuguo; Nie, Pulin; Wu, Yixiong

    2013-11-01

    The microstructure of the laser clad Inconel 718 alloy coating was observed by scanning electron microscope (SEM). The chemical composition of precipitation phases was investigated by energy dispersive spectrometer (EDS) and solid phase microextraction (SPME). The crystal structure and lattice constants of precipitation are determined by transmission electron microscope (TEM). Vickers hardness of the coatings and the nanohardness of the interstitial phases were measured. The insular carbide (MC) and the tetragonal nitride (MN) with face-centered cubic (FCC) structure are rich in Ti and Nb but depleted in Ni, Fe and Cr due to the interdiffusion and redistribution of alloying elements between MC and MN and supersaturated matrix. MC and MN were precipitated in the forms of (Nb0.12Ti0.88)C1.5 and (Nb0.88Ti0.12)N1.5, and the Gibbs free energies of formation can be expressed as Δ G [ (Nb0.12Ti0.88)C1.5 ] 0 = - 122.654 - 3.1332 T (kJ /mol) and Δ G [ (Nb0.88Ti0.12)N1.5 ] 0 = - 157.814 - 3.0251 T (kJ /mol). The nanohardness and Young's modulus of the MC and MN were much higher than the matrix, and the plastic deformation energy of interstitial phases was lower than the matrix. The precipitation of MC and MN is beneficial to the mechanical properties of coating.

  15. Theoretical investigation of the precipitation of δ' in Al-Li

    Science.gov (United States)

    Khachaturyan, A. G.; Lindsey, T. F.; Morris, J. W.

    1988-02-01

    This paper contains the results of a theoretical investigation of the equilibrium between a disordered fee solution and an Ll2 phase in a model binary alloy and the transformation paths that may be followed when the disordered phase is quenched into the two-phase field. The results are specifically applied to binary Al-Li alloys, in which case the ordered phase is the metastable Al3Li (δ') phase that precipitates from the disordered solid solution (α). The thermodynamic model assumes that the atoms interact in pairs with an interaction potential that is independent of the temperature and composition, and uses the “mean field approximation” for the entropy of mixing. The assumptions confine its applicability to temperatures well below the ordering temperature of the Ll2 phase. The model is used to compute the two-phase field that separates the disordered solution and the Ll2 phase. For the specific case of Al-Li, it provides results that fit the available experimental data and offer a simple explanation for the observed deviation from stoichiometry of the δ' phase. The model predicts that the disordered solution orders congruently on quenching, but is then unstable with respect to decom-position by a spinodal mechanism that leads ultimately to a state of ordered Ll2 precipitates in a disordered matrix. The results provide plausible interpretations for the transformations observed in quenched Al-Li alloys.

  16. Effect of Copper and Bronze Addition on Corrosion Resistance of Alloyed 316L Stainless Steel Cladded on Plain Carbon Steel by Powder Metallurgy

    Institute of Scientific and Technical Information of China (English)

    Wenjue CHEN; Yueying WU; Jianian SHEN

    2004-01-01

    A sandwich structure with cladding alloyed 316L stainless steel on plain carbon steel was prepared by means of powder metallurgy (PM) processing. Electrolytic Cu and prealloyed bronze (95Cu wt pct, 5Sn wt pct) were added in different contents up to 15% into the surface cladded 316L layers and the effect of alloying concentrations on the corrosion resistance of the 316L cladding layers was studied. The corrosion performances of the cladding samples were studied by immersion tests and potentio-dynamic anodic polarization tests in H2SO4 and FeCl3 solutions. Both 316L and alloyed 316L surface layers with 1.0 mm depth produced by PM cladding had an effect to improve corrosion resistance in H2SO4 and FeCl3 solutions. Small Cu and bronze addition (4%) had a positive effect in H2SO4 and FeCl3 solutions. 4% Cu alloyed 316L surface layer produced by PM cladding showed similar anodic polarization behaviour to the 316L cladding layer in H2SO4 and FeCl3 solutions.

  17. 钛合金的激光表面硬化%Laser Cladding Coaters on Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    戈彦劼; 王慧萍

    2013-01-01

    钛合金具有良好的机械性能、生物相容性和耐腐蚀性能,已用于航空结构材料和牙科功能材料.但应用中发现钛合金硬度低、不耐磨损的缺陷.本文在钛合金表面制备TiC为主的激光熔覆层,自行设计了两种预涂粉层的成分,相应地制备了(TiC+ Ti)和(TiC+Ti+ F102)两种熔覆层.经各种检测和分析得知:(TiC+Ti+ F102)熔覆层有可能用于钛合金的航空结构材料;而(TiC+Ti)熔覆层有希望用于牙科功能材料,但需要进一步做模拟试验和装机(或临床)试验.%Titanium alloy has good mechanical properties, organisms compatibility and corrosion resistance, and has been applied in structural materials for aerospace and dental materials. However, in actual application, it is found that the titanium alloy is not hard enough and not wear resistance. In this paper, the laser cladding TiC composite coating on the surface of TC4 alloy was gained, two compositions of pre coating layer were designed, and the laser cladding TiC + Ti and TiC + Ti + F102 composite coating on the surface of TC4 alloy was obtained. The laser cladding TiC + Ti + F102 composite coating have many applications as structural materials for aerospace and the laser cladding TiC + Ti can be expected to be applied as dental materials. However, further simulation tests and clinical tests are required.

  18. Microstructure of Nano-Y2O3/Cobalt Based Alloy Composite Coating by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    何宜柱; 李明喜; 袁晓敏; 斯松华

    2004-01-01

    Composite coatings made of nano-Y2O3/cobalt-based alloy and produced by crosscurrent CO2 laser on Ni-based superalloy are introduced. Cross-section or surface of the coatings was examined to reveal their microstructure using optical microscope,SEM,including EDS microanalysis,TEM and XRD. The results show that some equilibrium or non-equilibrium phases,such as γ-Co,Cr23C6,Y2O3 and ε-Co exist in the coatings. Fine and short dendritic microstructure and columnar to equiaxed transition (CET) occurred by adding nano-Y2O3 particles. With the increasing amount of nano-Y2O3(1%,mass fraction),fully equiaxed crystallization appeared. These are caused by nano-Y2O3 particles acting as new nucleation site and rapid solidification of the melt. The results also show that inhomogeneous dispersion of nano-Y2O3 results in the formation of ε-Co phase in the coatings. The sub-microstructure of the clad is stacking fault. The mechanism of the formation of equiaxed grains is also analyzed.

  19. First Principles Study of Al-Li Intermetallic Compounds

    Science.gov (United States)

    Yu, Hai-li; Duan, Xiao-hui; Ma, Yong-jun; Zeng, Min

    2012-12-01

    The structural properties, heats of formation, elastic properties, and electronic structures of four compositions of binary Al-Li intermetallics, Al3Li, AlLi, Al2Li3, and Al4Li9, are analyzed in detail by using density functional theory. The calculated formation heats indicate a strong chemical interaction between Al and Li for all the Al-Li intermetallics. In particular, in the Li-rich Al-Li compounds, the thermodynamic stability of intermetallics linearly decreases with increasing concentration of Li. According to the computational single crystal elastic constants, all the four Al-Li intermetallic compounds considered here are mechanically stable. The polycrystalline elastic modulus and Poisson's ratio have been deduced by using Voigt, Reuss, and Hill approximations, and the calculated ratios of bulk modulus to shear modulus indicate that the four compositions of binary Al-Li intermetallics are brittle materials. With the increase of Li concentration, the bulk modulus of Al-Li intermetallics decreases in a linear manner.

  20. Influence of yttrium on microstructure and properties of Ni–Al alloy coatings prepared by laser cladding

    Directory of Open Access Journals (Sweden)

    Cun-shan Wang

    2014-03-01

    Full Text Available Ni–Al alloy coatings with different Y additions are prepared on 45# medium steel by laser cladding. The influence of Y contents on the microstructure and properties of Ni–Al alloy coatings is investigated using X-ray diffraction, scanning electron microscopy, electron probe microanalyzer, Vickers hardness tester, friction wear testing machine, and thermal analyzer. The results show that the cladding layers are mainly composed of NiAl dendrites, and the dendrites are gradually refined with the increase in Y additions. The purification effect of Y can effectively prevent Al2O3 oxide from forming. However, when the atomic percent of Y addition exceeds 1.5%, the extra Y addition will react with O to form Y2O3 oxide, even to form Al5Y3O12 oxide, depending on the amount of Y added. The Y addition in a range of 1.5–3.5 at.% reduces the hardness and anti-attrition of cladding layer, but improves obviously its wear and oxidation resistances.

  1. Influence of yttrium on microstructure and properties of NieAl alloy coatings prepared by laser cladding

    Institute of Scientific and Technical Information of China (English)

    Cun-shan WANG

    2014-01-01

    NieAl alloy coatings with different Y additions are prepared on 45# medium steel by laser cladding. The influence of Y contents on the microstructure and properties of NieAl alloy coatings is investigated using X-ray diffraction, scanning electron microscopy, electron probe microanalyzer, Vickers hardness tester, friction wear testing machine, and thermal analyzer. The results show that the cladding layers are mainly composed of NiAl dendrites, and the dendrites are gradually refined with the increase in Y additions. The purification effect of Y can effectively prevent Al2O3 oxide from forming. However, when the atomic percent of Y addition exceeds 1.5%, the extra Y addition will react with O to form Y2O3 oxide, even to form Al5Y3O12 oxide, depending on the amount of Y added. The Y addition in a range of 1.5e3.5 at.%reduces the hardness and anti-attrition of cladding layer, but improves obviously its wear and oxidation resistances.

  2. Dynamics of Gradient Bioceramic Composite Coating on Surface of Titanium Alloy by Wide-Band Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    LIU Qi-bin; ZOU Long-jiang; ZHU Wei-dong; LI Hai-tao; DONG Chuang

    2004-01-01

    The gradient bioceramic coating was prepared on the surface of titanium alloy using wide-band laser cladding. The dynamics of gradient bioceramic composite coating containing hydroxyapatite (HA) prepared with mixture of CaHPO4*2H2O and CaCO3 under the condition of wide-band laser was studied theoretically. The corresponding mathematical model and its numerical solution were presented. The examination experiment showed that HA bioceramic composite coatings can be obtained by appropriately choosing wide-band laser cladding parameters. The microstructure and surface morphology of HA bioceramic coating were observed by SEM and X-ray diffraction. The experimental results showed that the bioceramic coating is composed of HA, β-TCP, CaO, CaTiO3 and TiO2. The surface of bioceramic coating takes coral-shaped structure or short-rod piled structure, which helps osteoblast grow into bioceramic and improves the biocompatibility.

  3. Nickel Base Alloy Strip Electroslag Cladding of Nuclear Power Equipment%核电设备中的镍基合金带极电渣堆焊

    Institute of Scientific and Technical Information of China (English)

    李双燕

    2011-01-01

    以Inconel 690镍基合金堆焊为例,简述了堆焊工艺评定、模拟件试验和产品应用,结果表明:带极电渣堆焊可用于压水堆核电站核岛主设备蒸汽发生器管板大面积镍基合金堆焊.%Taking Inconel 690 nickel base alloy strip cladding for example,the cladding procedure qualification test, mock ?up test and product application were briefly described. Test results indicate that strip electroslag cladding technology can apply to large area nickel base alloy cladding on tube - sheet of steam generators for pressurized water reactor nuclear power plant nuclear island main equipment.

  4. Laser cladding of Zr-based coating on AZ91D magnesium alloy for improvement of wear and corrosion resistance

    Indian Academy of Sciences (India)

    Kaijin Huang; Xin Lin; Changsheng Xie; T M Yue

    2013-02-01

    To improve the wear and corrosion resistance of AZ91D magnesium alloy, Zr-based coating made of Zr powder was fabricated on AZ91D magnesium alloy by laser cladding. The microstructure of the coating was characterized by XRD, SEM and TEM techniques. The wear resistance of the coating was evaluated under dry sliding wear test condition at room temperature. The corrosion resistance of the coating was tested in simulated body fluid. The results show that the coating mainly consists of Zr, zirconium oxides and Zr aluminides. The coating exhibits excellent wear resistance due to the high microhardness of the coating. The main wear mechanism of the coating and the AZ91D sample are different, the former is abrasive wear and the latter is adhesive wear. The coating compared to AZ91D magnesium alloy exhibits good corrosion resistance because of the good corrosion resistance of Zr, zirconium oxides and Zr aluminides in the coating.

  5. Online monitoring of thermo-cycles and its correlation with microstructure in laser cladding of nickel based super alloy

    Science.gov (United States)

    Muvvala, Gopinath; Patra Karmakar, Debapriya; Nath, Ashish Kumar

    2017-01-01

    Laser cladding, basically a weld deposition technique, is finding applications in many areas including surface coatings, refurbishment of worn out components and generation of functionally graded components owing to its various advantages over conventional methods like TIG, PTA etc. One of the essential requirements to adopt this technique in industrial manufacturing is to fulfil the increasing demand on product quality which could be controlled through online process monitoring and correlating the signals with the mechanical and metallurgical properties. Rapid thermo-cycle i.e. the fast heating and cooling rates involved in this process affect above properties of the deposited layer to a great extent. Therefore, the current study aims to monitor the thermo-cycles online, understand its variation with process parameters and its effect on different quality aspects of the clad layer, like microstructure, elemental segregations and mechanical properties. The effect of process parameters on clad track geometry is also studied which helps in their judicious selection to deposit a predefined thickness of coating. In this study Inconel 718, a nickel based super alloy is used as a clad material and AISI 304 austenitic steel as a substrate material. The thermo-cycles during the cladding process were recorded using a single spot monochromatic pyrometer. The heating and cooling rates were estimated from the recorded thermo-cycles and its effects on microstructures were characterised using SEM and XRD analyses. Slow thermo-cycles resulted in severe elemental segregations favouring Laves phase formation and increased γ matrix size which is found to be detrimental to the mechanical properties. Slow cooling also resulted in termination of epitaxial growth, forming equiaxed grains near the surface, which is not preferred for single crystal growth. Heat treatment is carried out and the effect of slow cooling and the increased γ matrix size on dissolution of segregated elements in

  6. Dynamic and kinetic properties of Al-Li melts

    Science.gov (United States)

    Kiselev, A. I.

    2008-12-01

    The dynamic and kinetic properties of Al-Li melts are calculated. The liquid phase of this system is shown to be characterized by three states with different ion distributions and different degrees of electron localization.

  7. Eutectic reaction analysis between TRU-50%Zr alloy fuel and HT-9 cladding, and temperature prediction of eutectic reaction under steady-state

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Woan; Lee, Byoung Oon; Lee, Bong Sang; Park, Won Seok

    2001-02-01

    Blanket fuel assembly for HYPER contains a bundle of pins arrayed in triangular pitch, which has hexagonal bundle structure. The reference blanket fuel pin consists of the fuel slug of TRU-50wt%Zr alloy and the cladding material of ferritic martensite steel, HT-9. Chemical interaction between fuel slug and cladding is one of the major concerns in metallic fuel rod design. The contact of metallic fuel slug and stainless steel cladding in a fuel rod forms a complex multi-component diffusion couple at elevated temperatures. The potential problem of inter-diffusion of fuel and cladding components is essentially two-fold weakening of cladding mechanical strength due to the formation of diffusion zones in the cladding, and the formation of comparatively low melting point phases in the fuel/cladding interface to develop eutectic reaction. The main components of fuel slug are composed of zirconium alloying element in plutonium matrix, including neptunium, americium and uranium additionally. Therefore basic eutectic reaction change of Pu-Fe binary system can be assessed, while it is estimated how much other elements zirconium, uranium, americium and neptunium influence on plutonium phase stability. Afterwards it is needed that eutectic reaction is verified through experimental necessarily.

  8. Incorporation of Integral Fuel Burnable Absorbers Boron and Gadolinium into Zirconium-Alloy Fuel Clad Material

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, K.; Renk, T.J.; Lahoda, E.J.; Corradini, M.L

    2004-12-14

    Long-lived fuels require the use of higher enrichments of 235U or other fissile materials. Such high levels of fissile material lead to excessive fuel activity at the beginning of life. To counteract this excessive activity, integral fuel burnable absorbers (IFBA) are added to some rods in the fuel assembly. The two commonly used IFBA elements are gadolinium, which is added as gadolinium-oxide to the UO2 powder, and boron, which is applied as a zirconium-diboride coating on the UO2 pellets using plasma spraying or chemical vapor deposition techniques. The incorporation of IFBA into the fuel has to be performed in a nuclear-regulated facility that is physically separated from the main plant. These operations tend to be very costly because of their small volume and can add from 20 to 30% to the manufacturing cost of the fuel. Other manufacturing issues that impact cost and performance are maintaining the correct levels of dosing, the reduction in fuel melting point due to gadolinium-oxide additions, and parasitic neutron absorption at fuel's end-of-life. The goal of the proposed research is to develop an alternative approach that involves incorporation of boron or gadolinium into the outer surface of the fuel cladding material rather than as an additive to the fuel pellets. This paradigm shift will allow for the introduction of the IFBA in a non-nuclear regulated environment and will obviate the necessity of additional handling and processing of the fuel pellets. This could represent significant cost savings and potentially lead to greater reproducibility and control of the burnable fuel in the early stages of the reactor operation. The surface alloying is being performed using the IBEST (Ion Beam Surface Treatment) process developed at Sandia National Laboratories. IBEST involves the delivery of energetic ion beam pulses onto the surface of a material, near-surface melting, and rapid solidification. The non-equilibrium nature of such processing allows for

  9. Research on residual stress inside Fe-Mn-Si shape memory alloy coating by laser cladding processing

    Science.gov (United States)

    Ju, Heng; Lin, Cheng-xin; Zhang, Jia-qi; Liu, Zhi-jie

    2016-09-01

    The stainless Fe-Mn-Si shape memory alloy (SMA) coating was prepared on the surface of AISI 304 stainless steel. The principal residual stress measured by the mechanical hole-drilling method indicates that the Fe-Mn-Si SMA cladding specimen possesses a lower residual stress compared with the 304 stainless steel cladding specimen. The mean stress values of the former and the latter on 10-mm-thick substrate are 4.751 MPa and 7.399 MPa, respectively. What's more, their deformation values on 2-mm-thick substrate are about 0° and 15°, respectively. Meanwhile, the variation trend and the value of the residual stress simulated by the ANSYS finite element software consist with experimental results. The X-ray diffraction (XRD) pattern shows ɛ-martensite exists in Fe-Mn-Si SMA coating, which verifies the mechanism of low residual stress. That's the γ→ɛ martensite phase transformation, which relaxes the residual stress of the specimen and reduces its deformation in the laser cladding processing.

  10. IN-SITU SYNTHETIC TiB2 PARTICULATE REINFORCED METAL MATRIX COMPOSITE COATING ON AA2024 ALUMINUM ALLOY BY LASER CLADDING TECHNOLOGY

    OpenAIRE

    JIANG XU; YIDE KAN; WENJIN LIU

    2005-01-01

    In order to improve the wear resistance of aluminum alloy, in-situ synthesized TiB2 and Ti3B4 peritectic composite particulate reinforced metal matrix composite, formed on a 2024 aluminum alloy by laser cladding with a powder mixture of Fe-coated Boron, Ti and Al, was successfully achieved using 3-KW CW CO2 laser. The chemical composition, microstructure and phase structure of the composite clad coating were analyzed by energy dispersive X-ray spectroscopy (EDX), SEM, AFM and XRD. The typical...

  11. Kinetics of Zr-alloy cladding oxidation in the mixture of air and steam at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Tae; Park, Kwang Heon; Park, Joo Young [Kyunghee University, Yongin (Korea, Republic of)

    2012-05-15

    In Fukushima Daiichi Nuclear Power Plant accident, No.4 plant was exploded by hydrogen explosion. There was a strong speculation about the possibility of the reaction between the overheated fuels and the steam-air mixture in the storage pool. Later, it turned out to be due to the hydrogen leaked from No.3 plant. However, the reaction of the hot fuels with the steam-air mixture became an important issue. There have been a lot of data accumulated about Zr-alloy interaction with steam. However, Zr-alloy interactions with air and steam-air mixtures have not been studied relatively much. In this study, we measured the oxidation kinetics of Zry-4 and Zirlo claddings in air, and steam-air mixtures, and analyzed the kinetics

  12. Microstructure of Cu-based Amorphous Composite Coatings on AZ91D Magnesium Alloy by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    Kaijin Huang; Changsheng Xie; T.M.Yue

    2009-01-01

    To improve the sliding wear resistance of AZ91D magnesium alloy, Cu-based amorphous composite coatings made of Cu47Ti34Zr11Ni8 and Cu47Ti34Zr11Ni8+20 wt pct SiC powders were fabricated on AZ91D magnesium alloy by laser cladding, respectively. SEM (scanning electron microscopy), EDS (energy dispersive X-ray spectroscopy), XRD (X-ray diffraction) and TEM (transmission electron microscopy) techniques were employed to study the phases of the coatings. The results show that the coatings mainly consist of amorphous phase and different intermetallic compounds. The reason of formation of amorphous phase and the function of SiC particles were explained in details.

  13. The design of cobalt-free, nickel-based alloy powder (Ni-3) used for sealing surfaces of nuclear power valves and its structure of laser cladding coating

    Energy Technology Data Exchange (ETDEWEB)

    Fu Geyan, E-mail: fugeyan@suda.edu.c [School of Mechanical and Electric Engineering, Soochow University, Suzhou 215021 (China); Liu Shuang [School of Mechanical and Electric Engineering, Soochow University, Suzhou 215021 (China); Fan Jiwei [School of Materials Science and Chemical Engineering, Zhongyuan University of Technology, Zhengzhou 450007 (China)

    2011-05-15

    Research highlights: The Ni-3 Co-free alloy coating prepared by laser welding. Ni-3 alloy has excellent combination with stainless steel base. Ni-3 alloy containing those strengthening phases could have excellent wear resistance and anti-oxidation ability at high temperature. - Abstract: To meet the demand of cobalt-free for the cladding coating materials used on sealing surface of nuclear power valves, a new Co-free, Ni-Cr based alloy powder (Ni-3) has been developed. It has been successfully coated on the surface of stainless steel as the strengthening layer. The XRD result reveals that the primary phase of cladding coating is Ni-based solid solution, and the carbides M{sub 7}C{sub 3} and M{sub 23}C{sub 6} as well as several A{sub 3}B types of {gamma}' strengthening phases. It indicates that the alloy possesses the high wear resistance, good corrosion resistance and high temperature tolerance. The test results suggest that the micro-hardness of Ni-3 corresponds to that of alloy Stellite 6 which containing cobalt and currently used as material for nuclear power valves. Hence, the developed Ni-3 alloy powder can be the hopeful candidate material for Co-free cladding material used on the surface of nuclear power valves; it can reduce the nuclear pollution and save the expensive metals.

  14. Effects of Rolling Reduction and Strength of Composed Layers on Bond Strength of Pure Copper and Aluminium Alloy Clad Sheets Fabricated by Cold Roll Bonding

    Directory of Open Access Journals (Sweden)

    Yoji Miyajima

    2014-01-01

    Full Text Available Three types of clad sheets, Cu/Al, Cu/AA5052, and Cu/AA5083, were produced by cold roll bonding with the rolling reduction of 50% and 75%. Tensile shear tests which give tensile shear strength were performed in order to assess the bond strength. Scanning electron microscopy was performed on the fractured interface produced by the tensile shear tests, which suggests that the fracture occurs within the Al alloy layer. The tensile shear strengths considering the area fraction of deposit of Al alloy on Cu side were compared with the shear stress converting from the ultimate tensile strengths. As a result, the tensile shear strength of the clad sheets is attributed to the shear strength of Al alloy layer close to the well bonded interface. A simple model was proposed that explains the effects of the rolling reduction and area fraction of deposit of Al alloy.

  15. Neutron Imaging Investigations of the Secondary Hydriding of Nuclear Fuel Cladding Alloys during Loss of Coolant Accidents

    Science.gov (United States)

    Grosse, M.; Roessger, C.; Stuckert, J.; Steinbrueck, M.; Kaestner, A.; Kardjilov, N.; Schillinger, B.

    The hydrogen concentration and distribution at both sides of the burst opening of cladding tubes used in three QUENCH-LOCA simulation bundle experiments were investigated by means of neutron radiography and tomography. The quantitative correlation between the total macroscopic neutron cross-section and the atomic number density ratio between hydrogen and zirconium was determined by testing calibration specimens with known hydrogen concentrations. Hydrogen enrichments located at the end of the ballooning zone of the tested tubes were detected in the inner rods of the test bundles. Nearly all of the peripheral claddings exposed to lower temperatures do not show such enrichments. This implies that under the conditions investigated a threshold temperature exists below which no hydrogen enrichments can be formed. In order to understand the hydrogen distribution a model was developed describing the processes occurring during loss of coolant accidents after rod burst. The general shape of the hydrogen distributions with a peak each side of the ballooning region is well predicted by this model whereas the absolute concentrations are underestimated compared to the results of the neutron tomography investigations. The model was also used to discuss the influence of the alloy composition on the secondary hydrogenation. Whereas the relations for the maximal hydrogen concentrations agree well for one and the same alloy, the agreement for tests with different alloys is less satisfying, showing that material parameters such as oxidation kinetics, phase transition temperature for the zirconium oxide, and yield strength and ductility at high temperature have to be taken into account to reproduce the results of neutron imaging investigations correctly.

  16. Microstructure and properties of Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys prepared by laser cladding

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Xing-Wu, E-mail: fallenrain922@163.com [Department of Materials Engineering, Sichuan College of Architectural Technology, Deyang 618000 (China); Liu, Chun-Ge [Department of Transportation and Municipal Engineering, Sichuan College of Architectural Technology, Deyang 618000 (China)

    2013-03-15

    Highlights: ► We use a new method (laser cladding) to prepare Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys. ► We studied the effect of Ni content on alloys’ properties. ► Alloys show high microhardness, excellent corrosion resistance and wear resistance. ► The laser cladding layers play a good protective effect on Q235 steel. -- Abstract: The Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys were prepared by laser cladding. Using metallurgical microscope, scanning electron microscopy with spectroscopy (SEM/EDS), X-ray diffraction, micro/Vickers hardness tester, electrochemical workstation and tribometer the structure and hardness, corrosion resistance and wear resistance of Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys were tested. The result shows that, Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloy samples consist of the cladding zone, bounding zone and heat affected zone. The bounding zone is between cladding layer and the substrate of a good combination; the cladding zone is composed mainly of axis crystal, nanocrystalline and fine white crystals. The Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys coating phase structure samples (FCC and BCC structure) due to high-entropy effect. The surface microhardness of Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys samples up to 1102 HV, about 4 times as the substrate, and the hardness increases with increasing Ni content. Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys coating has good corrosion resistance in 1 mol/L NaOH solution and 3.5% NaCl solution. With the increase of Ni content, the corrosion resistance first increases and then decreases. The relative wear resistance of Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys coating shows a first increased and then a decreased trend with the increase of Ni content. Both the hardness and ductility are affected by wear resistance. The coating can play a good protective role on substrate Q235 steel.

  17. STATIC RECRYSTALLIZATION AFTER HOT WORKING OF Al-Li ALLOYS

    OpenAIRE

    Gonçalves, M.; Sellars, C

    1987-01-01

    Small slabs of DC cast and homogenised 8090 and 8091 have been hot rolled in an experimental mill at temperatures in the range 300-500°C and subsequently solution treated at 550°C for times up to 48 hrs. Increase in rolling temperature leads to slower recrystallization, but the effect diminishes at long solution treatment times when the rolling temperature is above 400°C. Recrystallized grains are nearly equiaxed after rolling at temperatures below 400°C but are elongated after rolling at hig...

  18. HEAT-UP AND COOL-DOWN TEMPERATURE-DEPENDENT HYDRIDE REORIENTATION BEHAVIORS IN ZIRCONIUM ALLOY CLADDING TUBES

    Directory of Open Access Journals (Sweden)

    JU-JIN WON

    2014-10-01

    Full Text Available Hydride reorientation behaviors of PWR cladding tubes under typical interim dry storage conditions were investigated with the use of as-received 250 and 485ppm hydrogen-charged Zr-Nb alloy cladding tubes. In order to evaluate the effect of typical cool-down processes on the radial hydride precipitation, two terminal heat-up temperatures of 300 and 400°C, as well as two terminal cool-down temperatures of 200 and 300°C, were considered. In addition, two cooling rates of 2.5 and 8.0°C/min during the cool-down processes were taken into account along with zero stress or a tensile hoop stress of 150MPa. It was found that the 250ppm hydrogen-charged specimen experiencing the higher terminal heat-up temperature and the lower terminal cool-down temperature generated the highest number of radial hydrides during the cool-down process under 150MPa hoop tensile stress, which may be explained by terminal solid hydrogen solubilities for precipitation, and dissolution and remaining circumferential hydrides at the terminal heat-up temperatures. In addition, the slower cool-down rate generates the larger number of radial hydrides due to a cooling rate-dependent, longer residence time at a relatively high temperature that can accelerate the radial hydride nucleation and growth.

  19. Effects of Heat Treatment on Microstructure and Hardness of Laser Clad NiWCRE Alloy Layer

    Institute of Scientific and Technical Information of China (English)

    LIU Su-qin; HUANG Jin-liang; WANG Shun-xing; DONG Qi-ming

    2004-01-01

    The effects of heat treatment on microstructure and hardness of laser surface-clad Ni21+20%WC+0.5%CeO2 on the heat-resistant cast iron were investigated by means of X-ray diffraction(XRD), transmission electron microscope(TEM)and microhardness test. The experimental results showed that heat-treating at 500℃ has no effect on microstructure and hardness of the layers. Although the phase composition of the layers heat-treated at 700℃ and 800℃ remain unchanged,more Ni3B and Ni4B3 phases are precipitated on the matrix of the cladding layer, the metastable phase-M7C3 is transformed into steady phase-M23C6, and the precipitated phases coarsened.

  20. Effects of Heat Treatment on Microstructure and Hardness of Laser Clad NiWCRE Alloy Layer

    Institute of Scientific and Technical Information of China (English)

    LIUSu-qin; HUANGJin-liang; WANGShun-xing; DONGQi-ming

    2004-01-01

    The ettects of heat treatment on microstructure and hardness ot laser surface-clad Ni21+20%WC+0.5%CeO2 on the heat-resistant cast iron were investigated by means of X-ray diffraction(XRD), transmission electron microscope(TEM) and microhardness test. The experimental results showed that heat-treating at 500℃ has no effect on microstructure and hardness of the layers. Although the phase composition of the layers heat-treated at 700℃ and 800℃ remain unchanged, more Ni3B and Ni4B3 phases are precipitated on the matrix of the cladding layer, the metastable phase-M7C3 is transformed into steady phase-M23C6, and the precipitated phases coarsened.

  1. Microstructure and Tribological Properties of In Situ Synthesized TiN Reinforced Ni/Ti Alloy Clad Layer Prepared by Plasma Cladding Technique

    Science.gov (United States)

    Jin, Guo; Li, Yang; Cui, Huawei; Cui, Xiufang; Cai, Zhaobing

    2016-06-01

    A Ni/Ti composite coating enhanced by an in situ synthesized TiN phase was fabricated on FV520B steel by plasma cladding technology. The in situ formation of the TiN phase was confirmed by XRD, SEM, and TEM. The cladding layer consisted of three regions on going from the top to the bottom, namely, columnar grain regions, columnar dendritic regions, and fine grain regions. The cladding layer was composed of Ni3Ti, TiN, (Fe, Ni), and Ti phases. The dendritic and columnar regions were mainly composed of the Ni3Ti and (Fe, Ni) phases. The Ti phase was observed at the branches of dendrite crystals and columnar grains. The volume fraction of the TiN phase in the cladding layer was about 3.2%. The maximum micro-hardness value of the in situ formed coating (760 HV0.2) was higher than that of the pure coating (537 HV0.2). The cladding layer had a small amount of scratch and wear debris when a load of 20 N was used. As the test load increased, the wear debris in the cladding layer also increased and the massive furrows were not observed.

  2. A comparative wear study on Al-Li and Al-Li/SiC composite

    Science.gov (United States)

    Okumus, S. Cem; Karslioglu, Ramazan; Akbulut, Hatem

    2013-12-01

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al2O3 ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms-1 and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

  3. Structure-Induced Covalent Bonding in Al-Li Compounds

    Science.gov (United States)

    Nozawa, Kazuki; Ishii, Yasushi

    2010-06-01

    Formation mechanism of a deep pseudogap in the electronic density of states of the Al-Li Bergman and Zintl compounds is discussed with an emphasis on the differences among isostructural Al-Mg compounds. Since Li scatters electrons very weakly in comparison with Al and Mg, the potential landscape for electrons in Al-Li compounds is not that of the entire close-packed structure but that of the Al sublattice, which is a rather porous network like the diamond lattice. The porous network structure realized by the chemical decoration of close-packed structures enhances the covalent nature of electronic structures, hence the deep pseudogap in the electronic density of states. A concept of structure-induced covalent bonding in a network realized by the chemical decoration of close-packed structures may provide a novel picture in the electronic structures of complex intermetallic compounds.

  4. Micro-, meso- and macro-texture and fatigue crack roughness in Al-Li 2090 T8E41

    Energy Technology Data Exchange (ETDEWEB)

    Haase, J.D.; Guvenilir, A.; Witt, J.R.; Stock, S.R. [Georgia Inst. of Tech., Atlanta, GA (United States)

    1998-12-31

    The use of synchrotron polychromatic x-ray microbeams in the transmission geometry is described for mapping grain orientation as a function of position and for relating this microtexture to the formation of large asperities on fatigue crack surfaces in Al-Li 2090 T8E41. In common with the centers of rolled plates of many aluminum alloys, Al-Li 2090 T8E41 has a sharp average texture or macrotexture different from that in the outer portions of the plate. The geometry of large asperities in Al-Li 2090 has been related to this macrotexture, and the resulting roughness-induced crack closure is recognized to be responsible for the very low crack propagation rates in certain plate orientations. This report focuses on why asperities form at certain positions and why the crack remains relatively planar elsewhere. The microtexture (i.e., the grain-to-grain orientation variation) seems to be organized into a specific type of mesotexture: multiple adjacent grains have nearly identical orientations and form substantial volumes of near-single-crystal material. Transitions between differently oriented near-single-crystal volumes or between a near-single-crystal region and more randomly oriented grains appear to bound asperities.

  5. The Role of X-Ray Diffraction for Analyzing Zr-Sn-Nb-Fe Alloys as Power Reactor Fuel Cladding

    Directory of Open Access Journals (Sweden)

    Sugondo

    2010-08-01

    Full Text Available Synthesis of Zr-1%Nb-1%Sn-1%Fe alloy is undertaken in order to develop fuel cladding alloy at high burn-up. Powder specimens of Zr-Sn-Nb-Fe alloy were prepared and then formed into pellets with a dimension of 10 mm in height 10 mm in diameter using a pressure of 1.2 ton/cm2. The 5 gram green pellets were then melted in an arc furnace crucible under argon atmosphere. The pressure in the furnace was set at 2 psi and the current was 50 A. Afterwards, the ingots were heated at a temperature of 1100°C for 2 hours and subsequently quenched in water. The ingots then underwent annealing at temperatures of 400°C, 500°C, 600°C, 700°C, and 750°C for 2 hours. The specimens were analyzed using X-ray diffraction in order to construct diffractograms. Results of the diffraction patterns were fitted with data from JCPDF (Joint Committee Powder Diffraction File to determine the type of crystals in the elements or substances. The greater the crystallite dimension, the smaller the dislocation density. Agreeable results for hardening or strengthening were obtained at annealing temperatures of 500°C and 700, whereas for softening or residual stress at 600°C and 750°C. The nucleation of the secondary phase precipitate (SPP was favourable at annealing temperatures of 400°C, 500°C, and 700°C. For Zr-1%Nb-1%Sn-1%Fe alloy with annealing temperatures between 400°C to 800°C, precipitates of Fe2Nb, ZrSn2,FeSn, SnZr, NbSn2, Zr0.68Nb0.25Fe0.08, Fe2Nb0.4Zr0.6, Fe37Nb9Zr54, and ω-Zr were observed. Satisfactory precipitate stabilization was achieved at annealing temperature of 800°C, growth of precipitates at temperature between 500°C to 600°C, and minimization of precipitate size at 700°C.

  6. Past research and fabrication conducted at SCK•CEN on ferritic ODS alloys used as cladding for FBR's fuel pins

    Science.gov (United States)

    De Bremaecker, Anne

    2012-09-01

    -destructive tests (ultrasonic and eddy currents) were also developed. In-pile creep in argon and in liquid sodium was deeply studied on pressurized segments irradiated up to 75 dpaNRT. Finally two fuel assemblies cladded with such ODS alloys were irradiated in Phenix to the max dose of 90 dpa. Creep deformation and swelling were limited but the irradiation-induced embrittlement became acute. The programme was stopped shortly after the Chernobyl disaster, before the embrittlement problem was solved.

  7. Explosive Cladding of Titanium and Aluminium Alloys on the Example of Ti6Al4V-AA2519 Joints / Wybuchowe Platerowanie Stopów Tytanu I Aluminium Na Przykładzie Połączenia Ti6Al4V-AA2519

    Directory of Open Access Journals (Sweden)

    Gałka A.

    2015-12-01

    Full Text Available Explosive cladding is currently one of the basic technologies of joining metals and their alloys. It enables manufacturing of the widest range of joints and in many cases there is no alternative solution. An example of such materials are clads that include light metals such as titanium and aluminum. ach new material combination requires an appropriate adaptation of the technology by choosing adequate explosives and tuning other cladding parameters. Technology enabling explosive cladding of Ti6Al4V titanium alloy and aluminum AA2519 was developed. The clads were tested by means of destructive and nondestructive testing, analyzing integrity, strength and quality of the obtained joint.

  8. Alloy Selection for Accident Tolerant Fuel Cladding in Commercial Light Water Reactors

    Science.gov (United States)

    Rebak, Raul B.

    2015-12-01

    As a consequence of the March 2011 events at the Fukushima site, the U.S. congress asked the Department of Energy (DOE) to concentrate efforts on the development of nuclear fuels with enhanced accident tolerance. The new fuels had to maintain or improve the performance of current UO2-zirconium alloy rods during normal operation conditions and tolerate the loss of active cooling in the core for a considerably longer time period than the current system. DOE is funding cost-shared research to investigate the behavior of advanced steels both under normal operation conditions in high-temperature water [ e.g., 561 K (288 °C)] and under accident conditions for reaction with superheated steam. Current results show that, under accident conditions, the advanced ferritic steels (1) have orders of magnitude lower reactivity with steam, (2) would generate less hydrogen and heat than the current zirconium alloys, (3) are resistant to stress corrosion cracking under normal operation conditions, and (4) have low general corrosion in water at 561 K (288 °C).

  9. Results of U-xMo (x=7, 10, 12 wt.%) Alloy versus Al-6061 Cladding Diffusion Couple Experiments Performed at 500, 550 and 600 Degrees C

    Energy Technology Data Exchange (ETDEWEB)

    Emmanuel Perez; Dennis D. Keiser, Jr.; Yongho Sohn

    2013-04-01

    The Reduced Enrichment for Research and Test Reactors (RERTR) program has been developing low enrichment fuel systems encased in Al 6061 for use in research and test reactors. U–Mo alloys in contact with Al and Al alloys can undergo diffusional interactions that can result in the development of interdiffusion zones with complex fine-grained microstructures composed of multiple phases. A monolithic fuel currently being developed by the RERTR program has local regions where the U–Mo fuel plate is in contact with the Al 6061 cladding and, as a result, the program finds information about interdiffusion zone development at high temperatures of interest. In this study, the microstructural development of diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo, and U-12wt.%Mo vs. Al 6061 (or 6061 aluminum) cladding, annealed at 500, 550, 600 degrees C for 1, 5, 20, 24, or 132 hours, was analyzed by backscatter electron microscopy and x-ray energy dispersive spectroscopy on a scanning electron microscope. Concentration profiles were determined by standardized wavelength dispersive spectroscopy and standardless x-ray energy dispersive spectroscopy. The results of this work shows that the presence of surface layers at the U–Mo/Al 6061 interface can dramatically impact the overall interdiffusion behavior in terms of rate of interaction and uniformity of the developed interdiffusion zones. It further reveals that relatively uniform interaction layers with higher Si concentrations can develop in U–Mo/Al 6061 couples annealed at shorter times and that longer times at temperature result in the development of more non-uniform interaction layers with more areas that are enriched in Al. At longer annealing times and relatively high temperatures, U–Mo/Al 6061 couples can exhibit more interaction compared to U–Mo/pure Al couples. The minor alloying constituents in Al 6061 cladding can result in the development of many complex phases in the interaction layer of U

  10. A new theoretical model for high power laser clad TiC/NiCrBSiC composite coatings on Ti6Al4V alloys

    Science.gov (United States)

    Lei, Yiwen; Sun, Ronglu; Lei, Jianbo; Tang, Ying; Niu, Wei

    2010-09-01

    A new three-dimensional model was proposed to simulate the high power laser clad TiC/NiCrBSiC composite coatings on Ti6Al4V alloys using commercial finite element analysis software. Powders of TiC, NiCrBSiC alloy and cuboid of Ti6Al4V alloys were taken as sample materials. The dilution rate, the melt pool, and the heat affected zone (HAZ) of the substrate under different incident laser power were obtained from the calculation and compared with the microstructure of the coatings. The simulated results show that a good quality laser clad TiC/NiCrBSiC composite coating with low dilution rate and excellent metallurgical bond can be prepared under the processing parameters as follows: scanning velocity 5 mm/s, laser beam diameter 4.5 mm and incident laser power 2500 W. There exhibits an excellent agreement between the simulated results and experimental data. It indicates that the new model is helpful to optimize the processing parameters to form a good quality coating.

  11. 快堆先进包壳材料ODS合金发展研究%R &D on advanced cladding materials ODS alloys for fast reactor

    Institute of Scientific and Technical Information of China (English)

    崔超; 黄晨; 苏喜平; 宿彦京

    2011-01-01

    Fast reactor advanced cladding materials ODS alloys (Oxide Dispersion Strengthened steel) have excellent irradiation swelling resistance and stable mechanical properties at elevated temperature, which is chosen as the candidate cladding material of high burnup fuel for fast reactor. This paper generally introduces the progress of R&D on ODS alloys, including the processing technology of ODS alloys, mechanical properties, compatibility with sodium, irradiation performance and so on.%快堆先进包壳材料ODS合金(Oxide Dispersion Strengthened Steel)具有优异的抗辐照肿胀性能和高温力学性能,是高性能快堆燃料元件包壳管的主要候选材料.本文概括介绍了ODS合金的研究进展,包括ODS合金的制备方法、力学性能、与钠相容性以及辐照性能等.

  12. Residual stress and crack initiation in laser clad composite layer with Co-based alloy and WC + NiCr

    Science.gov (United States)

    Lee, Changmin; Park, Hyungkwon; Yoo, Jaehong; Lee, Changhee; Woo, WanChuck; Park, Sunhong

    2015-08-01

    Although laser cladding process has been widely used to improve the wear and corrosion resistance, there are unwanted cracking issues during and/or after laser cladding. This study investigates the tendency of Co-based WC + NiCr composite layers to cracking during the laser cladding process. Residual stress distributions of the specimen are measured using neutron diffraction and elucidate the correlation between the residual stress and the cracking in three types of cylindrical specimens; (i) no cladding substrate only, (ii) cladding with 100% stellite#6, and (iii) cladding with 55% stellite#6 and 45% technolase40s. The microstructure of the clad layer was composed of Co-based dendrite and brittle eutectic phases at the dendritic boundaries. And WC particles were distributed on the matrix forming intermediate composition region by partial melting of the surface of particles. The overlaid specimen exhibited tensile residual stress, which was accumulated through the beads due to contraction of the coating layer generated by rapid solidification, while the non-clad specimen showed compressive. Also, the specimen overlaid with 55 wt% stellite#6 and 45 wt% technolase40s showed a tensile stress higher than the specimen overlaid with 100% stellite#6 possibly, due to the difference between thermal expansion coefficients of the matrix and WC particles. Such tensile stresses can be potential driving force to provide an easy crack path ways for large brittle fractures combined with the crack initiation sites such as the fractured WC particles, pores and solidification cracks. WC particles directly caused clad cracks by particle fracture under the tensile stress. The pores and solidification cracks also affected as initiation sites and provided an easy crack path ways for large brittle fractures.

  13. Effects of Rolling Reduction and Strength of Composed Layers on Bond Strength of Pure Copper and Aluminium Alloy Clad Sheets Fabricated by Cold Roll Bonding

    OpenAIRE

    Yoji Miyajima; Kotaro Iguchi; Susumu Onaka; Masaharu Kato

    2014-01-01

    Three types of clad sheets, Cu/Al, Cu/AA5052, and Cu/AA5083, were produced by cold roll bonding with the rolling reduction of 50% and 75%. Tensile shear tests which give tensile shear strength were performed in order to assess the bond strength. Scanning electron microscopy was performed on the fractured interface produced by the tensile shear tests, which suggests that the fracture occurs within the Al alloy layer. The tensile shear strengths considering the area fraction of deposit of Al al...

  14. Fatigue Crack Growth Rate Test Results for Al-Li 2195 Parent Metal, Variable Polarity Plasma Arc Welds and Friction Stir Welds

    Science.gov (United States)

    Hafley, Robert A.; Wagner, John A.; Domack, Marcia S.

    2000-01-01

    The fatigue crack growth rate of aluminum-lithium (Al-Li) alloy 2195 plate and weldments was determined at 200-F, ambient temperature and -320-F. The effects of stress ratio (R), welding process, orientation and thickness were studied. Results are compared with plate data from the Space Shuttle Super Lightweight Tank (SLWT) allowables program. Data from the current series of tests, both plate and weldment, falls within the range of data generated during the SLWT allowables program.

  15. Residual stress and crack initiation in laser clad composite layer with Co-based alloy and WC + NiCr

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Changmin; Park, Hyungkwon; Yoo, Jaehong [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Changhee, E-mail: chlee@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Woo, WanChuck [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Park, Sunhong [Research Institute of Industrial Science & Technology, Hyo-ja-dong, Po-Hang, Kyoung-buk, San 32 (Korea, Republic of)

    2015-08-01

    Highlights: • Major problem, clad cracking in laser cladding process, was researched. • Residual stress measurements were performed quantitatively by neutron diffraction method along the surface of specimens. • Relationship between the residual stress and crack initiation was showed clearly. • Ceramic particle effect in the metal matrix was showed from the results of residual stress measurements. • Initiation sites of generating clad cracks were specifically studied in MMC coatings. - Abstract: Although laser cladding process has been widely used to improve the wear and corrosion resistance, there are unwanted cracking issues during and/or after laser cladding. This study investigates the tendency of Co-based WC + NiCr composite layers to cracking during the laser cladding process. Residual stress distributions of the specimen are measured using neutron diffraction and elucidate the correlation between the residual stress and the cracking in three types of cylindrical specimens; (i) no cladding substrate only, (ii) cladding with 100% stellite#6, and (iii) cladding with 55% stellite#6 and 45% technolase40s. The microstructure of the clad layer was composed of Co-based dendrite and brittle eutectic phases at the dendritic boundaries. And WC particles were distributed on the matrix forming intermediate composition region by partial melting of the surface of particles. The overlaid specimen exhibited tensile residual stress, which was accumulated through the beads due to contraction of the coating layer generated by rapid solidification, while the non-clad specimen showed compressive. Also, the specimen overlaid with 55 wt% stellite#6 and 45 wt% technolase40s showed a tensile stress higher than the specimen overlaid with 100% stellite#6 possibly, due to the difference between thermal expansion coefficients of the matrix and WC particles. Such tensile stresses can be potential driving force to provide an easy crack path ways for large brittle fractures

  16. The Effect of Dilution on Microsegregation in AWS ER NiCrMo-14 Alloy Welding Claddings

    Science.gov (United States)

    Miná, Émerson Mendonça; da Silva, Yuri Cruz; Dille, Jean; Silva, Cleiton Carvalho

    2016-12-01

    Dilution and microsegregation are phenomena inherent to claddings, which, in turn, directly affect their main properties. This study evaluated microsegregation in the fusion zone with different dilution levels. The overlays were welded by the TIG cold wire feed process. Dilution was calculated from the geometric characteristics of the claddings and from the conservation of mass equation using chemical composition measurements. Microsegregation was calculated using energy dispersive X-ray spectroscopy measurements of the dendrites and the chemical composition of the fusion zone. The dilution of the claddings was increased by reducing the wire feed rate. Fe showed potential to be incorporated into the solid phase ( k > 1), and this increased with the increase of dilution. Mo, in turn, was segregated into the liquid phase ( k < 1) and also increased with the increase of dilution. However, Cr and W showed a slight decrease in their partition coefficients ( k) with the increase of dilution.

  17. Evolution of microstructure and properties in laser cladding of a Ni-Cr-B-Si hardfacing alloy

    NARCIS (Netherlands)

    Hemmati, I.; Ocelík, V.; De Hosson, J.T.M.

    2011-01-01

    Ni-Cr-B-Si coatings are used in many industrial applications in order to improve wear and/or corrosion properties. These coatings have traditionally been deposited by thermal spray techniques but the laser cladding process is also being increasingly employed to produce Ni-Cr-B-Si coatings with super

  18. Aluminum-lithium alloy development for thixoforming

    Energy Technology Data Exchange (ETDEWEB)

    Sauermann, R.; Friedrich, B. [IME Process Metallurgy and Metal Recycling, RWTH Aachen Univ. (Germany); Puettgen, W.; Bleck, W. [IEHK Inst. for Ferrous Metallurgy, RWTH Aachen Univ. (Germany); Balitchev, E.; Hallstedt, B.; Schneider, J.M. [MCh Materials Chemistry, RWTH Aachen Univ. (Germany); Bramann, H.; Buehrig-Polaczek, A. [GI Foundry Inst., RWTH Aachen Univ. (Germany); Uggowitzer, P.J. [ETH Zuerich, Metal Physics and Technology (Germany)

    2004-12-01

    This paper presents a scientific contribution to the development of lightweight/high-performance Al-Li alloys suitable for semi-solid processing. Thermodynamic calculations identified the most promising compositions with focus on the solidus-liquidus interval, fraction of solid-versus-temperature and phase reactions. The synthesis of Al-Li precursor billets was performed by overpressure induction melting in controlled atmosphere. DTA and microstructure investigations on Al-Li specimens were carried out as well as thixocasting trials of demonstrator components. New rheocasting of Al-Li alloys was investigated to identify the potential of this alternative precursor material route. It is shown that specifically developed Al-Li alloys offer great potential for semi-solid manufacturing. (orig.)

  19. Effect of tool geometry and cutting parameters on delamination and thrust forces in drilling CFRP/Al-Li

    Science.gov (United States)

    El Bouami, Souhail; Habak, Malek; Franz, Gérald; Velasco, Raphaël; Vantomme, Pascal

    2016-10-01

    Composite materials are increasingly used for structural parts in the aeronautic industries. Carbon Fiber-Reinforced Plastics (CFRP) are often used in combination with metallic materials, mostly aluminium alloys. This raises new problems in aircraft assembly. Delamination is one of these problems. In this study, CFRP/Al-Li stacks is used as experimental material for investigation effect of interaction of cutting parameters (cutting speed and feed rate) and tool geometry on delamination and thrust forces in drilling operation. A plan of experiments, based on Taguchi design method, was employed to investigate the influence of tool geometry and in particular the point angle and cutting parameters on delamination and axial effort. The experimental results demonstrate that the feed rate is the major parameter and the importance of tool point angle in delamination and thrust forces in the stacks were shown.

  20. An Update on C458 Al-Li

    Science.gov (United States)

    Babel, Hank; Rioja, Robert

    2003-01-01

    The 1.8 Li content and consequently the 0.0945 lb.cu in density of C458 along with its higher modulus and good strength and toughness at ambient and cryogenic temperatures made it an attractive alloy for single and multiple use cryogenic tankage and unpressurized structure for space launch and operational vehicles. A major effort during the past year was directed towards establishing a production capability for C458 plate. Alcoa established a production ingot casting capability under Air Force Research Laboratory and NASA's Space Launch Initiative (SLI) sponsorship. Three heat lots of material were rolled so that the criterion for S-basis allowables could be met for AMS specifications. Lot acceptance testing showed that the strength and toughness values equaled and exceeded those obtained under the earlier Air Force Program when the alloy was developed. The details of this effort and the results achieved will be described. During the testing of compact tension specimens, particularly at cryogenic temperatures, delaminations were noted on the fractured surface. An investigation was initiated to better understand this condition. The results of this investigation will be presented which includes some of the successful production application of alloys with and without Li that exhibit this type of behavior.

  1. 16Mn钢表面激光熔覆Ni60合金关键参数优化%Optimization of key parameters for laser cladding Ni60 alloy on 16Mn steel surface

    Institute of Scientific and Technical Information of China (English)

    郑丽娟; 刘会莹; 李伟; 付宇明

    2012-01-01

    The temperature field during the process of laser cladding Ni60 alloy powder onto the 16Mn steel surface was numerical simulated by ANSYS software. The effect of laser cladding process parameters to the temperature field was analyzed. Proving the quality of the cladding layer and targeting at deeper hardened layer for the substrate surface, the process parameters of laser power and scanning speed were optimized and the rational cladding parameters were obtained. Experimental study of laser cladding shows that the optimized process parameters are more reasonable and the experimental results confirm the reliability of the numerical optimization results.%采用ANSYS有限元软件对16Mn钢表面激光熔覆Ni60合金过程中的温度场进行数值模拟,分析激光熔覆工艺参数对温度场的影响,并以保证熔覆层质量的前提下,使基体表面得到较深的硬化层为目标,对激光功率和扫描速度两个工艺参数进行优化设计,得到了最佳熔覆参数;激光熔覆实验研究发现,优化后的工艺参数较为合理,实验结果也证实了数值优化结果的可靠性.

  2. Ultrasonic Inspection for Zirconium Alloy Nuclear Fuel Cladding Tubes%核燃料锆合金包壳管的超声波探伤

    Institute of Scientific and Technical Information of China (English)

    夏健文; 韩承

    2016-01-01

    介绍压水堆核燃料锆合金包壳管(Φ10.0 mm×0.70 mm)的超声波自动探伤方法和工艺,讨论不同长度、宽度、深度、角度的纵向和横向人工缺陷的超声响应结果.通过对检测出缺陷的典型包壳管进行金相解剖,确定缺陷性质和实际尺寸,验证超声探伤结果.针对实际探伤中的问题,考虑质量和成本控制,提出对不同缺陷的验收准则.实践应用表明,现行探伤方法和工艺能检出管材不同位置处10μm级的微小缺陷.但受缺陷的类型、取向的影响,探伤仪检测得到的回波幅度并不能完全真实地反应缺陷的实际大小和性质,需要在实际探伤时针对管材的制造工艺水平采取适当的加严措施,对不同的缺陷加以控制,才能更好地保证核燃料包壳管的质量.%The cladding tube is the main component of the nuclear fuel assembly,and as the first protective barrier,its quality is very important for the safe operation of nuclear power plants.After the completion of cladding tubes,a non-destructive testing is required,in which the ultrasonic inspection is a primary method.This paper introduces the ultrasonic flaw testing method and techniques of the zirconium alloy nuclear fuel cladding tubes for pressurized water reactor (PWR),which used in automatic ultrasonic inspection equipment,and discusses the detector response to the longitudinal and transverse artificial defects of different length,width,depth and angle.Its actual shape and size are measured by metallographic anatomical analysis for some typical defects to confirm the flaw detection results.Consider its quality and cost control,the acceptance rules are proposed for different defects.The application shows that the existing detection method and process can inspect the fine defects about 10μm at different locations of the cladding tube.Due to the influence of the defect type and orientation,the echo amplitude obtained by the detector is not completely true to the

  3. A study of TiB2/TiB gradient coating by laser cladding on titanium alloy

    Science.gov (United States)

    Lin, Yinghua; Lei, Yongping; Li, Xueqiao; Zhi, Xiaohui; Fu, Hanguang

    2016-07-01

    TiB2/TiB gradient coating has been fabricated by a laser cladding technique on the surface of a Ti-6Al-4V substrate using TiB2 powder as the cladding material. The microstructure and mechanical properties of the gradient coating were analyzed by SEM, EPMA, XRD, TEM and an instrument to measure hardness. With the increasing distance from the coating surface, the content of TiB2 particles gradually decreased, but the content of TiB short fibers gradually increased. Meanwhile, the micro-hardness and the elastic modulus of the TiB2/TiB coating showed a gradient decreasing trend, but the fracture toughness showed a gradient increasing trend. The fracture toughness of the TiB2/TiB coating between the center and the bottom was improved, primarily due to the debonding of TiB2 particles and the high fracture of TiB short fibers, and the fracture position of TiB short fiber can be moved to an adjacent position. However, the debonding of TiB2 particles was difficult to achieve at the surface of the TiB2/TiB coating.

  4. TC4合金基体上激光熔敷钛、铝、二氧化硅碳粉末的显微组织%Microstructure of laser clad Ti+Al+SiO2+C powders on Ti6Al4V alloy

    Institute of Scientific and Technical Information of China (English)

    母久方; 胡芳友; 回丽; 何雪浤; 赵金

    2006-01-01

    Laser cladding experiment of Ti + Al + SiO2 + C was carried out on Ti6Al4V alloy substrate, thenthe microstructure of the clad layer was analyzed with SEM and its Anti - oxidation function was discussed.Analyses microstructure show that the clad coating can be divided into three zones along the depth direction:clad, binding and heat - affected zones. Ti5Si3 in the clad zone exists in the form of fine dendrites, TiAl matrix filling among Ti5Si3 dendrites plays a role of connecting the Ti5Si3 with the TiAl3 and transferring load,so the clad coating has been strengthened obviously.

  5. ZIRCONIUM-CLADDING OF THORIUM

    Science.gov (United States)

    Beaver, R.J.

    1961-11-21

    A method of cladding thorium with zirconium is described. The quality of the bond achieved between thorium and zirconium by hot-rolling is improved by inserting and melting a thorium-zirconium alloy foil between the two materials prior to rolling. (AEC)

  6. Development on Laser Cladding Ceramic Coating

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The latest progress and research status of laser cladding ceramic coating was summarized. Technique characteristics and influence factors of laser cladding technique were introduced. Laser cladding technique includes the mixing method and laser irradiation. The mixing method can be classified as pre-coating method and synchronization method. The technique parameters include size of facula, scanning speed, cladding sector and times, adding quantity of powder, thickness of coating and quantity of joint coating. The results show that proper technique parameters can be controlled in order to acquire high quality laser cladding coating. Strengthened effect mechanism of rare earth additive is concluded, and the main effects of rare earth additive are micro-alloying, purifying boundary, fining crystal grains, improving crystal boundary, restraining columnar crystal growing. The development of laser cladding ceramic coating research was discussed.

  7. Cladding tube manufacturing technology

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, R. [Kraftwerk Union AG, Mulheim (Germany); Jeong, Y.H.; Baek, B.J.; Kim, K.H.; Kim, S.J.; Choi, B.K.; Kim, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-04-01

    This report gives an overview of the manufacturing routine of PWR cladding tubes. The routine essentially consists of a series of deformation and annealing processes which are necessary to transform the ingot geometry to tube dimensions. By changing shape, microstructure and structure-related properties are altered simultaneously. First, a short overview of the basics of that part of deformation geometry is given which is related to tube reducing operations. Then those processes of the manufacturing routine which change the microstructure are depicted, and the influence of certain process parameters on microstructure and material properties are shown. The influence of the resulting microstructure on material properties is not discussed in detail, since it is described in my previous report 'Alloy Development for High Burnup Cladding.' Because of their paramount importance still up to now, and because manufacturing data and their influence on properties for other alloys are not so well established or published, the descriptions are mostly related to Zry4 tube manufacturing, and are only in short for other alloys. (author). 9 refs., 46 figs.

  8. Characteristics of laser clad α-Ti/TiC+(Ti,W)C1-x/Ti2SC+TiS composite coatings on TA2 titanium alloy

    Science.gov (United States)

    Zhai, Yong-Jie; Liu, Xiu-Bo; Qiao, Shi-Jie; Wang, Ming-Di; Lu, Xiao-Long; Wang, Yong-Guang; Chen, Yao; Ying, Li-Xia

    2017-03-01

    TiC reinforced Ti matrix composite coating with Ti2SC/TiS lubricant phases in-situ synthesized were prepared on TA2 titanium alloy by laser cladding with different powder mixtures: 40%Ti-19.5%TiC-40.5%WS2, 40%Ti-25.2%TiC-34.8%WS2, 40%Ti-29.4%TiC-30.6%WS2 (wt%). The phase compositions, microstructure, microhardness and tribological behaviors and wear mechanisms of coatings were investigated systematically. Results indicate that the main phase compositions of three coatings are all continuous matrix α-Ti, reinforced phases of (Ti,W)C1-x and TiC, lubricant phases of Ti2SC and TiS. The microhardness of the three different coatings are 927.1 HV0.5, 1007.5 HV0.5 and 1052.3 HV0.5, respectively. Compared with the TA2 titanium alloy (approximately 180 HV0.5), the microhardness of coatings have been improved dramatically. The coefficients of friction and the wear rates of those coatings are 0.41 and 30.98×10-5 mm3 N-1 m-1, 0.30 and 18.92×10-5 mm3 N-1 m-1, 0.34 and 15.98×10-5 mm3 N-1 m-1, respectively. Comparatively speaking, the coating fabricated with the powder mixtures of 40%Ti-25.2%TiC-34.8%WS2 presents superior friction reduction and anti-wear properties and the main wear mechanisms of that are slight plastic deformation and adhesive wear.

  9. Non-destructive Residual Stress Analysis Around The Weld-Joint of Fuel Cladding Materials of ZrNbMoGe Alloys

    Directory of Open Access Journals (Sweden)

    Parikin

    2003-08-01

    Full Text Available The residual stress measurements around weld-joint of ZrNbMoGe alloy have been carried out by using X-ray diffraction technique in PTBIN-BATAN. The research was performed to investigate the structure of a cladding material with high temperature corrosion resistance and good weldability. The equivalent composition of the specimens (in %wt. was 97.5%Zr1%Nb1%Mo½%Ge. Welding was carried out by using TIG (tungsten inert gas technique that completed butt-joint with a current 20 amperes. Three region tests were taken in specimen while diffraction scanning, While diffraction scanning, tests were performed on three regions, i.e., the weldcore, the heat-affected zone (HAZ and the base metal. The reference region was determined at the base metal to be compared with other regions of the specimen, in obtaining refinement structure parameters. Base metal, HAZ and weldcore were diffracted by X-ray, and lattice strain changes were calculated by using Rietveld analysis program. The results show that while the quantity of minor phases tend to increase in the direction from the base metal to the HAZ and to the weldcore, the quantity of the ZrGe phase in the HAZ is less than the quantity of the ZrMo2 phase due to tGe element evaporation. The residual stress behavior in the material shows that minor phases, i.e., Zr3Ge and ZrMo2, are more dominant than the Zr matrix. The Zr3Ge and ZrMo2 experienced sharp straining, while the Zr phase was weak-lined from HAZ to weldcore. The hydrostatic residual stress ( in around weld-joint of ZrNbMoGe alloy is compressive stress which has minimum value at about -2.73 GPa in weldcore region

  10. Nickel Base Alloy Cladding by Double Hot Wire TIG Welding Procedure on Tubesheet of Steam Generator%核电蒸汽发生器管板镍基合金双热丝钨极氩弧焊堆焊技术

    Institute of Scientific and Technical Information of China (English)

    罗成

    2012-01-01

    介绍了蒸汽发生器管板镍基合金堆焊新工艺——双热丝钨极氩弧焊,从热丝钨极氩弧焊的基本原理、堆焊材料的选择和堆焊工艺参数等方面作了基本论述.就双热丝钨极氩弧堆焊的使用,简述了堆焊工艺试验、工艺评定、预评定和产品应用的过程,说明镍基合金双热丝钨极氩弧焊在蒸发器管板上堆焊应用是成功的.%It is introduced that nickel - base alloy double hot wire TIG cladding procedure on tubesheet of steam generator. Those aspects are discussed basically from principle of double hot wire TIG cladding, choosing of cladding consumables and cladding parameters etc. Cladding test, procedure qualification, prequalification and product application for nickel base alloy double hot wire TIG cladding are described briefly. It is successful that application of nickel base alloy double hot wire TIG cladding procedure on tubesheet of steam generators.

  11. Nuclear fuel elements having a composite cladding

    Science.gov (United States)

    Gordon, Gerald M.; Cowan, II, Robert L.; Davies, John H.

    1983-09-20

    An improved nuclear fuel element is disclosed for use in the core of nuclear reactors. The improved nuclear fuel element has a composite cladding of an outer portion forming a substrate having on the inside surface a metal layer selected from the group consisting of copper, nickel, iron and alloys of the foregoing with a gap between the composite cladding and the core of nuclear fuel. The nuclear fuel element comprises a container of the elongated composite cladding, a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, an enclosure integrally secured and sealed at each end of said container and a nuclear fuel material retaining means positioned in the cavity. The metal layer of the composite cladding prevents perforations or failures in the cladding substrate from stress corrosion cracking or from fuel pellet-cladding interaction or both. The substrate of the composite cladding is selected from conventional cladding materials and preferably is a zirconium alloy.

  12. Effect of CeO2 and Y2O3 on microstructure, bioactivity and degradability of laser cladding CaO-SiO2 coating on titanium alloy.

    Science.gov (United States)

    Li, H C; Wang, D G; Chen, C Z; Weng, F

    2015-03-01

    To solve the lack of strength of bulk biomaterials for load-bearing applications and improve the bioactivity of titanium alloy (Ti-6Al-4V), CaO-SiO2 coatings on titanium alloy were fabricated by laser cladding technique. The effect of CeO2 and Y2O3 on microstructure and properties of laser cladding coating was analyzed. The cross-section microstructure of ceramic layer from top to bottom gradually changes from cellular-dendrite structure to compact cellular crystal. The addition of CeO2 or Y2O3 refines the microstructure of the ceramic layer in the upper and middle regions. The refining effect on the grain is related to the kinds of additives and their content. The coating is mainly composed of CaTiO3, CaO, α-Ca2(SiO4), SiO2 and TiO2. Y2O3 inhibits the formation of CaO. After soaking in simulated body fluid (SBF), the calcium phosphate layer is formed on the coating surface, indicating the coating has bioactivity. After soaking in Tris-HCl solution, the samples doped with CeO2 or Y2O3 present a lower weight loss, indicating the addition of CeO2 or Y2O3 improves the degradability of laser cladding sample.

  13. Microstructures and dissolution of carbides occurring during the laser cladding of steel with tungsten carbide reinforced Ni- and Co-hard-alloys; Gefuegeausbildung und Karbidaufloesung beim Laserbeschichten von Stahl mit Wolframkarbid-verstaerkten Ni- und Co-Hartlegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Luft, A. [Fraunhofer-Inst. fuer Werkstoffphysik und Schichttechnologie, Dresden (Germany); Techel, A. [Fraunhofer-Inst. fuer Werkstoffphysik und Schichttechnologie, Dresden (Germany); Nowotny, S. [Fraunhofer-Inst. fuer Werkstoffphysik und Schichttechnologie, Dresden (Germany); Reitzenstein, W. [Fraunhofer-Inst. fuer Werkstoffphysik und Schichttechnologie, Dresden (Germany)

    1995-05-01

    Wear resistant layers on steel were produced by laser cladding of powder mixtures consisting of a Ni- or Co-base hard alloy and coarse grained WC or fused tungsten carbide, respectively. The microstructure of the clad composite layers were investigated by metallography, SEM, EDX and image analysis. The four binder/carbide systems were found to differ strongly in the degree of partial carbide dissolution and the formation of new hard phases. (orig.) [Deutsch] Verschleissfeste Schutzschichten auf Stahl werden durch Laserbeschichten mit Pulvergemischen aus einer Ni- bzw. Co-Hartlegierung und grobkoernigem WC bzw. Wolframschmelzkarbid hergestellt. Die erzeugten Dispersionsgefuege werden mittels Metallographie, REM, EDX und Bildanalyse untersucht. Der Vergleich der vier Schichtsysteme liefert deutliche Unterschiede im Ausmass der Karbidaufloesung und der Bildung neuer Hartphasen. (orig.)

  14. Study of localized corrosion in aluminum alloys by the scanning reference electrode technique

    Science.gov (United States)

    Danford, M. D.

    1995-01-01

    Localized corrosion in 2219-T87 aluminum (Al) alloy, 2195 aluminum-lithium (Al-Li) alloy, and welded 2195 Al-Li alloy (4043 filler) have been investigated using the relatively new scanning reference electrode technique (SRET). Anodic sites are more frequent and of greater strength in the 2195 Al-Li alloy than in the 2219-T87 Al alloy, indicating a greater tendency toward pitting for the latter. However, the overall corrosion rates are about the same for these two alloys, as determined using the polarization resistance technique. In the welded 2195 Al-Li alloy, the weld bean is entirely cathodic, with rather strongly anodic heat affected zones (HAZ) bordering both sides, indicating a high probability of corrosion in the HAZ parallel to the weld bead.

  15. Testing of uranium nitride fuel in T-111 cladding at 1200 K cladding temperature

    Science.gov (United States)

    Rohal, R. G.; Tambling, T. N.; Smith, R. L.

    1973-01-01

    Two groups of six fuel pins each were assembled, encapsulated, and irradiated in the Plum Brook Reactor. The fuel pins employed uranium mononitride (UN) in a tantalum alloy clad. The first group of fuel pins was irradiated for 1500 hours to a maximum burnup of 0.7-atom-percent uranium. The second group of fuel pins was irradiated for about 3000 hours to a maximum burnup of 1.0-atom-percent uranium. The average clad surface temperature during irradiation of both groups of fuel pins was approximately 1200 K. The postirradiation examination revealed the following: no clad failures or fuel swelling occurred; less than 1 percent of the fission gases escaped from the fuel; and the clad of the first group of fuel pins experienced clad embrittlement whereas the second group, which had modified assembly and fabrication procedures to minimize contamination, had a ductile clad after irradiation.

  16. First principle calculation of Al, Li and intermetallic compounds for Al-Li system%Al-Li系统性质的第一原理计算

    Institute of Scientific and Technical Information of China (English)

    陈红梅; 范常有; 方杰; 刘奕新; 欧阳义芳; 杜勇; 贺跃辉

    2009-01-01

    用第一原理方法对铝、锂及铝锂二元系统金属间化合物的稳定和亚稳相的原子体积、弹性性质及形成焓等热力学性质进行了计算,结果表明:计算的平均原子体积略大于实验值,计算的体积模量与已有的实验值符合得比较好,对铝锂系统来说,计算的体积模量随锂的浓度的增加单调下降.对铝锂系统的稳定和亚稳定相的形成焓的计算表明,最稳定相为B32结构的Al-Li金属间化合物.%The lattice constants, elastic properties and thermodynamic properties of aluminum, lithium and intermetallic compound for Al-Li system were calculated with density function theo-ry. The calculated lattice constants, elastic constants, isothermal bulk modulus and properties of dimer for aluminum and lithium agree very well with the experimental data. The calculated for-mation enthalpies and isothermal bulk moduli of Al-Li intermetallic compounds are in good agree-ment with the experimental data and the results of other theoretical results available.

  17. Strain hardening and jump-like deformation of ultrafine polycrystalline Al-Li solid solutions at 0.5 K

    Science.gov (United States)

    Isaev, N. V.; Shumilin, S. E.; Zabrodin, P. A.; Geidarov, V. G.; Grigorova, T. V.; Fomenko, V. S.; Braude, I. S.; Pustovalov, V. V.

    2013-07-01

    This is a study of the effect of microstructure created by severe plastic deformation (SPD) and annealing on strain hardening and jump-like deformation in Al-Li alloys. It is shown that under tension at 0.5 K, SPD processed polycrystals retain a significant strain hardening rate and have high strength and ductility. SPD also simulates unstable (jump-like) flow of the polycrystals owing to dislocation dynamics that shows up as stress jumps in the tension curve. The average amplitude of the jumps increases with strain, while the dislocation amplitude distribution corresponds to collective motion of dislocation avalanches with a distinctive scale. Jump-like deformation is partially suppressed by high-temperature annealing, while the distribution of the jump amplitudes is described by a power law. The relationship established between the coefficient of strain hardening and the average stress jump amplitude suggests a common dislocation dynamic for strain hardening and jump-like deformation at low temperatures. The observed features of low-temperature plastic deformation are treated as a consequence of changes in the grain sizes and density of dislocations owing to SPD and annealing.

  18. 激光重熔处理对AZ31镁合金表面特性的影响%Effects of Laser Cladding Treatment on Surface Performance of AZ31 Magnesium Alloy

    Institute of Scientific and Technical Information of China (English)

    卫中山; 刘六法

    2011-01-01

    Effects of laser cladding treatment on surface performance of AZ31 magnesium alloy sheet were observed by the help of Nd-YAG laser. Rapid melting-solidification occurs on the surface of the AZ31 magnesium alloy sheet, and treated surface is composed of re-melting zone and heat history zone.Grain size is apparently refined in the re-melting zone, and hardness is increased by 5 % compared to that of the matrix. Immersing corrosion experiment shows that corrosion resistance of AZ31 magnesium alloy with laser cladding treatment is greatly improved in 3.5 % NaC1 solution, which is attributed to grain refinement in re-melting zone and enrichment of Al element in cladding surface.%使用Nd-YAG激光器对AZ31镁合金板材表面进行了激光重熔处理,分析了激光重熔处理对其表面特性的影响.在激光扫描时,试样表面发生了快速熔凝,处理层可分为重熔区、热影响区两部分.重熔区的晶粒得到明显细化,硬度比基体提高5%.腐蚀试验表明,AZ31镁合金在激光重熔处理后,在3.5%的NaCl溶液中的耐蚀性得到明显改善.重熔区晶粒细化和Al元素富集是激光重熔表面处理提高其耐蚀性的主要因素.

  19. Microstructure and wear behavior of γ/Al 4C 3/TiC/CaF 2 composite coating on γ-TiAl intermetallic alloy prepared by Nd:YAG laser cladding

    Science.gov (United States)

    Liu, Xiu-Bo; Shi, Shi-Hong; Guo, Jian; Fu, Ge-Yan; Wang, Ming-Di

    2009-03-01

    As a further step in obtaining high performance elevated temperature self-lubrication anti-wear composite coatings on TiAl alloy, a novel Ni-P electroless plating method was adopted to encapsulate the as-received CaF 2 in the preparation of precursor NiCr-Cr 3C 2-CaF 2 mixed powders with an aim to decrease its mass loss and increase its compatibility with the metal matrix during a Nd:YAG laser cladding. The microstructure of the coating was examined using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) and the friction and wear behavior of the composite coatings sliding against the hardened 0.45% C steel ring was evaluated using a block-on-ring wear tester at room temperature. It was found that the coating had a unique microstructure consisting of primary dendrites TiC and block Al 4C 3 carbides reinforcement as well as fine isolated spherical CaF 2 solid lubrication particles uniformly dispersed in the NiCrAlTi ( γ) matrix. The good friction-reducing and anti-wear abilities of the laser clad composite coating was suggested to the Ni-P electroless plating and the attendant reduction of mass loss of CaF 2 and the increasing of it's wettability with the NiCrAlTi ( γ) matrix during the laser cladding process.

  20. Study of the uniform corrosion of an aluminium alloy used for the fuel cladding of the Jules Horowitz experimental reactor; Etude de la corrosion uniforme d'un alliage d'aluminium utilise comme gainage du combustible nucleaire du reacteur experimental Jules Horowitz

    Energy Technology Data Exchange (ETDEWEB)

    Wintergerst, M. [CEA Saclay, Dept. des Materiaux pour le Nucleaire (DEN/DANS/DMN/SEMI), 91 - Gif-sur-Yvette (France)

    2008-07-01

    For the Jules Horowitz new material testing reactor, an aluminium base alloy, AlFeNi, will be used for the cladding of the fuel plates. Taking into account the thermal properties of the alloy and of its oxide, the corrosion of the fuel cans presents many problems. The aim of this thesis is to provide a growing kinetic of the oxide layer at the surface of the AlFeNi fuel can in order to predict the life time of fuel element. Thus the mechanism of degradation of the cladding will be describe in order to integrate the different parameters of the operating reactor. (A.L.B.)

  1. Thermal Stress Analysis of Welded Joint in 1420 Al-Li Alloy Induced by Thermal Cycling

    Institute of Scientific and Technical Information of China (English)

    Hongbin GENG; Song HE; Dezhuang YANG

    2003-01-01

    A model of double grains under plane stress state has been established. According to the double grain model, thermal stress induced by thermal cycling in welding fusion zone is numerically simulated by finite element method, and the microstructures before

  2. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    Ocelik, V.; Pei, Y.T.; de Hosson, J.T.M.; Popoola, O; Dahotre, NB; Midea, SJ; Kopech, HM

    2003-01-01

    Two functionally graded coatings were prepared by different laser surface engineering techniques. Laser cladding of AlSi40 powder leads to the formation of functionally graded material (FGM) coating on AI-Si cast alloy substrate. Mapping of strain fields near the laser clad track using the digital i

  3. Rolling process and bonding mechanism of micro-arc oxidation 6061 aluminium alloy clad plate%微弧氧化6061铝合金复合板轧制工艺及结合机理

    Institute of Scientific and Technical Information of China (English)

    郑艺; 吴国瑞; 张胜超; 张学术; 杨猛

    2014-01-01

    Micro-arc oxidation 6061 aluminium alloy clad plate was prepared by rolling which confirm the rolling composite feasibility of aluminum alloy plate .Bonding strength of the plate was tested by tear method and stripped surface was analyzed by SEM and EDS .The results show that aluminum alloy plate and micro-arc oxidation 6061 aluminium alloy plate can be bonded by rolling at the condition of rolling tempreture above 400 ℃and rolling reduction above 40%.During rolling, hardened layer on the aluminium alloy plate surface and ceramic layer on the micro-arc oxidation aluminium alloy plate surface ruptures , and ceramic particles involving in the interface bonding position , thus let the fresh aluminum alloy of the two plates extrude and the metallurgical bonding is obtained .%用轧制法制备了内含微弧氧化陶瓷颗粒的6061铝合金复合板,证实了微弧氧化铝合金板轧制复合可行性。用撕裂法测试了复合板的结合强度,对复合板剥离面进行了SEM和EDS分析。结果表明,在热轧温度不低于400℃,同时压下率不低于40%的轧制条件下,铝合金板/微弧氧化铝合金板通过轧制可以实现结合。在轧制时铝合金表面硬化层、微弧氧化铝合金表面陶瓷层破裂,陶瓷颗粒卷入界面结合处,复合板两侧铝合金新鲜金属挤出实现冶金结合。

  4. Microstructure and Wear Resistance of Laser Cladding TiC Coat on Titanium Alloy%钛合金表面激光熔覆TiC涂层显微结构和耐磨性

    Institute of Scientific and Technical Information of China (English)

    王慧萍; 李军; 李芳; 李曼萍; 奚文龙

    2012-01-01

    采用HL-5000型横流CO2激光加工机在TC4钛合金表面激光熔覆TiC+ Ti和TiC+Ti+ F102复合涂层.通过SEM、EDAX、XRD、HXD-1000TMC型显微硬度计,HT-600型高温摩擦磨损试验机,分析了熔覆层的显微组织、成分、物相,测试了激光熔覆层的显微硬度和滑动摩擦磨损性能.结果表明,激光熔覆制备的TiC复合涂层与基体呈冶金结合,在TiC+ Ti激光熔覆层中,熔覆层的组织是在Ti基体上分布着TiC树枝晶;在TiC +Ti+ F102激光熔覆层中,TiC颗粒发生了部分溶解,熔覆层的组织是在Ti基和γ-Ni基的基体上分布着细小的TiC颗粒和TiC树枝晶.TiC+ Ti激光熔覆层的硬度约为700 HV0.1,TiC+Ti+ F102激光熔覆层的硬度约为800 HV0.1,两种复合涂层耐磨性均比TC4钛合金显著提高.%The laser cladding TiC + Ti and TiC + Ti + F102 composite coaling on the surfact of TC4 alloy was obtained with 5.0 Kw continuous wave CO2 laser. The microstructure,composition and phase of the coating were investigated by means of SEM,EDAX,XRD,HXD-1000TMC Microhardness Tester, HT-600 wear machine Moreover, the microhardness and friction wear properties was measured. The results indicate that the laser cladding TiC composite coating is well bonded with the matrix alloy. The microstructures of TiC dendrites in Ti matrix in the clad layer of TiC + Ti laser clad coating. For TiC + Ti + F102 laser clad coating, parts of TiC particles are dissolved to form a microstructures of TiC particles and fine TiC dendrites in the matrix of Ti and y-Ni in the clad layer. The microhardness of TiC + Ti coating is 700 HV0.1. The microhardness of TiC + Ti + F102 coating is 800 HV0.1 , and the coating greatly enhances the wear resistantce of TC4 titanium alloy.

  5. Mechanical Property and Oxidation Behavior of ATF cladding developed in KAERI

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Gil; Kim, Il-Hyun; Jung, Yang-Il; Park, Dong-Jun; Park, Jung-Hwan; Park, Jeong-Yong; Koo, Yang-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    To realize the coating cladding, coating material (Cr-based alloy) as well as coating technology (3D laser coating and arc ion plating combined with vacuum annealing) can be developed to meet the fuel cladding criteria. The coated Zr cladding can be produced after the optimization of coating technologies. The coated cladding sample showed the good oxidation/corrosion and adhesion properties without the spalling and/or severe interaction with the Zr alloy cladding from the various tests. Thus, it is known that the mechanical property and oxidation behavior of coated cladding concept developed in KAERI is reasonable for applying the ATF cladding in LWRs. At the present time various ATF concepts have been proposed and developing in many countries. The ATF concepts with potentially improved accident performance can be summarized to the coating cladding, Mo-Zr cladding, FeCrAl cladding, and SiCf/SiC cladding. Regarding the cladding performance, ATF cladding concepts will be evaluated with respect to the accident scenarios and normal operations of LWRs as well as to the fuel cladding fabrication.

  6. Investigation on Behavior of Rare Earth Element Cerium in Aluminum-Lithium Alloys by Internal Friction Method

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The behavior of rare earth element Ce in 2090 Al-Li alloys was studied by the method of low frequency internal friction.The results showed that rare earth element Ce can increase the activation energy of grain boundary and improve the grain boundary strength of alloys.Rare earth element Ce can decrease the tendency of softening of elastic modulus of 2090 Al-Li alloys after heat cycle and keep high elastic modulus of initial state.

  7. Evaluation of Corrosion of Aluminum Based Reactor Fuel Cladding Materials During Dry Storage

    Energy Technology Data Exchange (ETDEWEB)

    Peacock, H.B. Jr.

    1999-10-21

    This report provides an evaluation of the corrosion behavior of aluminum cladding alloys and aluminum-uranium alloys at conditions relevant to dry storage. The details of the corrosion program are described and the results to date are discussed.

  8. Functionally graded materials with laser cladding

    NARCIS (Netherlands)

    de Hosson, J.T.M.; Pei, Y.T.; Brebbia, CA

    2001-01-01

    Al-40 w/o Si functionally graded materials (FGMs) were produced by a onestep laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surro

  9. Functionally graded materials produced by laser cladding

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2000-01-01

    AlSi40 functionally graded materials (FGMs) were produced by a one-step laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surrounded

  10. Functionally Graded Materials Produced by Laser Cladding

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2000-01-01

    AlSi40 functionally graded materials (FGMs) were produced by a one-step laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surrounded

  11. Thick tool steel coatings with laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; de Oliveira, U.; De Hosson, J. Th. M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2007-01-01

    This paper concentrates on thick and crack-free laser clad coatings (up to 3 mm). The coating material is a chromium-molybdenum-tungsten-vanadium alloyed high-speed steel that shows high wear resistance, high compressive strength, good toughness, very good dimensional stability on heat treatment and

  12. Investigation of laser cladding Cu/Cr Alloy on AA6061 Aluminum%AA6061铝基材上激光熔覆Cu/Cr合金层的研

    Institute of Scientific and Technical Information of China (English)

    丁健君; 郑恢俊

    2001-01-01

    在易氧化的纯Al表面制备Cu/Cr合金熔覆层,因二者的熔点温度差别大且容易在结合过渡区产生脆性裂纹而有一定难度。本文通过扫描电镜(SEM)分析研究了激光工艺参数对Cu/Cr熔覆层过渡区裂纹倾向的影响。实验结果表明,以1.06μm波长的Nd:YAG激光器的聚焦光束为热源,通过选择合适的激光工艺参数,可获得理想的Cu/Cr合金熔覆层,这对于改进铝材表面的物理、化学性能并进一步开发其作为电接触材料具有应用价值。%The laser cladding Cu/Cr alloy layers on commercial pure aluminum AA6061 which exposed to the atmosphere rapidly oxidizes,it is hardly to deal with since their melting points are quite different and the cracks are easily induced in the bound zone of cladding layers.This paper investigated the influences of laser process parameters on cracking trend in the bound zone by means of scanning electron microscope (SEM).The results indicate:the Cu/Cr cladding layers with pores and crack free can be prepared on Al substrates by the focusing Nd:YAG laser beam as a heating source under suitable laser process parameters,which is very useful to improve the surface properties of aluminum and furthermore to spread the applied values of aluminum as the electronic contacts.

  13. 钛合金表面激光熔覆h-BN固体润滑涂层%Solid Self-lubricating Coatings on TC4 Titanium Alloy by Laser Cladding with h-BN

    Institute of Scientific and Technical Information of China (English)

    王培; 叶源盛

    2015-01-01

    目的:优化钛合金激光熔覆固体润滑涂层的熔覆工艺参数,提高钛合金表面耐磨性能。方法采用Nd:YAG激光器,分别在高功率和低功率条件下,在TC4钛合金表面制备h-BN固体自润滑涂层。观察分析熔覆陶瓷层的宏观形貌、物相组成、显微组织和硬度,采用摩擦磨损试验仪对熔覆层的摩擦学性能进行研究。结果低激光功率下,熔覆材料上浮流失严重,熔覆层的相成分主要是TiN,TiB,TiB2等硬质相,硬度较高,存在裂纹。高激光功率下,基材的熔化稀释较好地抑制了润滑相h-BN的上浮,减少了溅射损失,发生了包晶反应,生成了单质金属Ti,熔覆层硬度低,但摩擦磨损试验表明,涂层中润滑相h-BN含量的增加使得形成了更好的润滑膜,降低了摩擦系数。结论在输出电流400 A,脉宽5 ms,频率12 Hz,扫描速度120 mm/min,搭接率50%~60%的条件下进行激光熔覆,所得熔覆层的表面状态平整,耐摩擦性能最好。%ABSTRACT:Objective To optimize the process parameters for laser cladding of solid self-lubricating coatings on titanium alloy, and improve the surface wear resistance of titanium alloy. Methods Using the Nd: YAG laser, h-BN ( hexagonal boron nitride) solid self-lubricating coatings were prepared on the surface of TC4 titanium alloy under conditions of high power and low power, re-spectively. The macro morphology, layer phase composition, microstructure, hardness and wear resistance of the ceramic layer were analyzed, and the tribological property of the ceramic layer was studied using a friction and wear tester. Results At low laser power, there was severe floating loss of cladding material, and the phase composition of the cladding layer was mainly composed of TiN, TiB, TiB2 and other hard phase components, the hardness was relatively high, with the presence of cracks. At high laser power, melting of the substrate inhibited the floating of the lubricating phase h-BN, reducing the

  14. Microstructure Evolution and Wear Behavior of the Laser Cladded CoFeNi2V0.5Nb0.75 and CoFeNi2V0.5Nb High-Entropy Alloy Coatings

    Science.gov (United States)

    Jiang, Li; Wu, Wei; Cao, Zhiqiang; Deng, Dewei; Li, Tingju

    2016-04-01

    The high-entropy alloy (HEA) coatings have received considerable attentions owing to their unique structures and properties caused by the quick solidification. In this work, the CoFeNi2V0.5Nb0.75 and CoFeNi2V0.5Nb HEAs which show fully eutectic and hypereutectic microstructures in their casting samples were laser cladded on 304 stainless steel substrate with laser power of 1400, 1600, and 1800 W. Results show that the HEA coatings are composed of the FCC solid solution phase and the Fe2Nb-type Laves phase. The cladding zones of the CoFeNi2V0.5Nb0.75 and CoFeNi2V0.5Nb coatings show cellular dendritic crystals, while the bonding zones show directional columnar crystals. Compared to the 304 stainless steel substrate, the HEA coatings show better wear resistance because of the combination of the hard Fe2Nb-type Laves phase and the ductile FCC solid solution matrix. Moreover, the HEA coatings with power of 1600 W show the best wear resistance attributing to the maximum volume fraction of the hard Fe2Nb-type Laves phase.

  15. AZ91 D镁合金表面激光熔覆Al-Cu合金的温度场模拟与验证%Simulation and Experimental Verification of Laser Cladding Temperature Field for Al-Cu Alloy on AZ91 D Magnesium Alloy Surface

    Institute of Scientific and Technical Information of China (English)

    朱润东; 李志勇; 李晓锡; 孙琪

    2014-01-01

    目的确定AZ91 D镁合金表面激光熔覆Al-Cu合金的最佳工艺参数。方法利用有限元软件ANSYS建立移动高斯热源作用下的温度场三维模型,对不同参数下激光熔覆过程中的温度场进行动态模拟,确定工艺参数。结果熔池中心的温度随着激光功率的增大而增大,随着热源移动速度和光斑直径的增大而减小。温度过高时,熔覆层下塌且内部出现裂纹;温度过低时,熔覆层上有大量的金属颗粒且内部含有夹杂物。结论当功率为240 W、扫描速度为2.5 mm/s、光斑直径为0.6 mm时,熔池中心的温度约为1100℃,熔覆层与基体接触面的温度约为700℃。在此参数下得到了表面成形光滑且与基体结合紧密的致密熔覆层。%ABSTRACT:Objective To get the optimal technological parameters for Al-Cu alloy cladded coatings on AZ91D magnesium alloy prepared by laser cladding. Methods The three-dimensional temperature field model of laser cladding under the moving GUASS heat source was established with ANSYS software. Then, the dynamic simulation of temperature field for laser cladding was conduc-ted under different technological parameters. And the technological parameters were optimized by contrasting the melting point of Al-Cu alloy and the welding pool temperature. Finally, the experimental verification was performed. Results The results showed that the temperature at the center of welding pool increased with the rise of power ( P) while decreased with the rise of the speed ( v) of heat source and the diameter( d) of facula. When the temperature was excessively high, the cladding layer was collapsed and with internal cracks. However, when the temperature was too low, the cladding layer was covered with large amount of metal particles, and there were internal inclusions. Conclusion Under the conditions of P=240 W, v=2. 5 mm/s and d=0. 6 mm, the temperature at the center of welding pool was about 1100 ℃, and the temperature at the

  16. Cladding embrittlement during postulated loss-of-coolant accidents.

    Energy Technology Data Exchange (ETDEWEB)

    Billone, M.; Yan, Y.; Burtseva, T.; Daum, R.; Nuclear Engineering Division

    2008-07-31

    The effect of fuel burnup on the embrittlement of various cladding alloys was examined with laboratory tests conducted under conditions relevant to loss-of-coolant accidents (LOCAs). The cladding materials tested were Zircaloy-4, Zircaloy-2, ZIRLO, M5, and E110. Tests were performed with specimens sectioned from as-fabricated cladding, from prehydrided (surrogate for high-burnup) cladding, and from high-burnup fuel rods which had been irradiated in commercial reactors. The tests were designed to determine for each cladding material the ductile-to-brittle transition as a function of steam oxidation temperature, weight gain due to oxidation, hydrogen content, pre-transient cladding thickness, and pre-transient corrosion-layer thickness. For short, defueled cladding specimens oxidized at 1000-1200 C, ring compression tests were performed to determine post-quench ductility at {le} 135 C. The effect of breakaway oxidation on embrittlement was also examined for short specimens oxidized at 800-1000 C. Among other findings, embrittlement was found to be sensitive to fabrication processes--especially surface finish--but insensitive to alloy constituents for these dilute zirconium alloys used as cladding materials. It was also demonstrated that burnup effects on embrittlement are largely due to hydrogen that is absorbed in the cladding during normal operation. Some tests were also performed with longer, fueled-and-pressurized cladding segments subjected to LOCA-relevant heating and cooling rates. Recommendations are given for types of tests that would identify LOCA conditions under which embrittlement would occur.

  17. Laser clad AlSiCuNi functionally graded coatings

    NARCIS (Netherlands)

    Pei, Yutao; de Hosson, J.T.M.; Brebbia, CA

    2001-01-01

    This paper presents an exploration of laser clad AlSiCuNi-alloy FGCs on cast Al-alloy substrates. SEM microstructure observations indicate that, besides Si primary particles, hard Al3Ni2 compounds also exhibits a continuous increase in both particle sizes and volume fractions from the bottom to the

  18. Hydrogen generation by the hydrolysis reaction of ball-milled aluminium-lithium alloys

    Science.gov (United States)

    Chen, Xingyu; Zhao, Zhongwei; Liu, Xuheng; Hao, Mingming; Chen, Ailiang; Tang, Zhongyang

    2014-05-01

    The addition of Li can prevent an inert alumina film from forming on the surface of Al alloy particles, allowing the rapid hydrogen generation of Al alloys to be achieved. However, because the Li content is less than 10%, the hydrogen generation rate and hydrogen yield of Al-Li alloys are significantly decreased. In this work, NaCl is introduced to prepare Al-Li alloys with low Li contents by ball milling. The research results show that by increasing the amount of NaCl added, the ball milling time and Li content can effectively improve the hydrogen generation of the alloys. Under optimal preparation conditions, the ultimate hydrogen yield of Al-Li alloys can reach 100%. The initial water temperature has almost no effect on the generation of hydrogen, even at 0 °C. Ca2+ and Mg2+ can combine with OH- to form the insoluble compounds Ca(OH)2 and Mg(OH)2, which can prevent hydrogen generation. NO3- reacts with Al to form ammonia and reduce the hydrogen yield of the alloys. Therefore, Al-Li alloys should be prevented from reacting with water containing Ca2+, Mg2+ and NO3-. Al-Li alloys must be stored in isolation from air to maintain good hydrogen-generation performances.

  19. 35CrMo steel surface by laser cladding Fe-based WC composite coating performance analysis

    Science.gov (United States)

    Zhou, Houming; Zhang, Haomin; Qin, Hengfeng

    2014-12-01

    The laser cladding technique in 35CrMo steel substrate prepared with different dosage under WC iron-based alloy cladding.Research the effects of different cladding WC addition on surface morphology, microstructure, microhardness and wear properties. The results show that 5% and 10% WC added amount of the surface quality of the cladding layer is preferably 15 % and 25 % of the volume of the WC surface of the cladding layer with varying degrees of cracks and pores, WC adding cladding layer can significantly improve the hardness. Through analysis we draw the conculation that,with 10% WC addition of iron-based alloy cladding the microhardness is 4.2 times the substrate , the relative wear resistance increased 4.1 than the substrate , enabling optimum cladding friction and wear properties.

  20. A defect density-based constitutive crystal plasticity framework for modeling the plastic deformation of Fe-Cr-Al cladding alloys subsequent to irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Patra, Anirban [Los Alamos National Laboratory; Wen, Wei [Los Alamos National Laboratory; Martinez Saez, Enrique [Los Alamos National Laboratory; Tome, Carlos [Los Alamos National Laboratory

    2016-02-05

    It is essential to understand the deformation behavior of these Fe-Cr-Al alloys, in order to be able to develop models for predicting their mechanical response under varied loading conditions. Interaction of dislocations with the radiation-induced defects governs the crystallographic deformation mechanisms. A crystal plasticity framework is employed to model these mechanisms in Fe-Cr-Al alloys. This work builds on a previously developed defect density-based crystal plasticity model for bcc metals and alloys, with necessary modifications made to account for the defect substructure observed in Fe-Cr-Al alloys. The model is implemented in a Visco-Plastic Self Consistent (VPSC) framework, to predict the mechanical behavior under quasi-static loading.

  1. Roll caster for the three-layer clad-strip

    OpenAIRE

    Nakamura, R; T. Yamabayashi; T. Haga; S. Kumai; H. Watari

    2010-01-01

    Purpose: of this paper is to show the characteristics of two kinds of roll casters for three-layer clad strip of aluminium alloys. Moreover, the characteristics of these twin roll casters were compeered with the early type of roll casters for clad strip.Design/methodology/approach: Design was tried to attain the fabrication of the roll casters to cast the three-layers-clad-strip. One caster was an unequal diameter roll caster equipped with a scraper. The scraper was adopted to prevent the mix...

  2. The Mechanical Response of Advanced Claddings during Proposed Reactivity Initiated Accident Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cinbiz, Mahmut N [ORNL; Brown, Nicholas R [ORNL; Terrani, Kurt A [ORNL; Lowden, Rick R [ORNL; ERDMAN III, DONALD L [ORNL

    2017-01-01

    This study investigates the failure mechanisms of advanced nuclear fuel cladding of FeCrAl at high-strain rates, similar to design basis reactivity initiated accidents (RIA). During RIA, the nuclear fuel cladding was subjected to the plane-strain to equibiaxial tension strain states. To achieve those accident conditions, the samples were deformed by the expansion of high strength Inconel alloy tube under pre-specified pressure pulses as occurring RIA. The mechanical response of the advanced claddings was compared to that of hydrided zirconium-based nuclear fuel cladding alloy. The hoop strain evolution during pressure pulses were collected in situ; the permanent diametral strains of both accident tolerant fuel (ATF) claddings and the current nuclear fuel alloys were determined after rupture.

  3. Characterization of Hydrogen Content in ZIRCALOY-4 Nuclear Fuel Cladding

    Science.gov (United States)

    Pfeif, E. A.; Lasseigne, A. N.; Krzywosz, K.; Mader, E. V.; Mishra, B.; Olson, D. L.

    2010-02-01

    Assessment of hydrogen uptake of underwater nuclear fuel clad and component materials will enable improved monitoring of fuel health. Zirconium alloys are used in nuclear reactors as fuel cladding, fuel channels, guide tubes and spacer grids, and are available for inspection in spent fuel pools. With increasing reactor exposure zirconium alloys experience hydrogen ingress due to neutron interactions and water-side corrosion that is not easily quantified without destructive hot cell examination. Contact and non-contact nondestructive techniques, using Seebeck coefficient measurements and low frequency impedance spectroscopy, to assess the hydrogen content and hydride formation within zircaloy 4 material that are submerged to simulate spent fuel pools are presented.

  4. Development of advanced LWR fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong Hwan; Park, S. Y.; Lee, M. H. [and others

    2000-04-01

    This report describes the results from evaluating the preliminary Zr-based alloys to develop the advanced Zr-based alloys for the nuclear fuel claddings, which should have good corrosion resistance and mechanical properties at high burn-up over 70,000MWD/MTU. It also includes the results from the basic studies for optimizing the processes which are involved in the development of the advanced Zr-based alloys. Ten(10) kinds of candidates for the alloys of which performance is over that of the existing Zircaloy-4 or ZIRLO alloy were selected out of the preliminary alloys of 150 kinds which were newly designed and repeatedly manufactured and evaluated to find out the promising alloys. First of all, the corrosion tests on the preliminary alloys were carried out to evaluate their performance in both pure water and LiOH solution at 360 deg C and in steam at 400 deg C. The tensile tests were performed on the alloys which proved to be good in the corrosion resistance. The creep behaviors were tested at 400 deg C for 10 days with the application of constant load on the samples which showed good performance in the corrosion resistance and tensile properties. The effect of the final heat treatment and A-parameters as well as Sn or Nb on the corrosion resistance, tensile properties, hardness, microstructures of the alloys was evaluated for some alloys interested. The other basic researches on the oxides, electrochemical properties, corrosion mechanism, and the establishment of the phase diagrams of some alloys were also carried out.

  5. Material Selection for Accident Tolerant Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Snead, Lance Lewis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    Alternative cladding materials to Zr-based alloys are being investigated for accident tolerance, which can be defined as > 100X improvement (compared to Zr-based alloys) in oxidation resistance to steam or steam-H2 environments at ≥ 1200°C for short times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800°C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. However, commercial Ti2AlC that was not single phase, formed a much thicker oxide at 1200°C in steam and significant TiO2, and therefore Ti2AlC may be challenging to form as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475°C, while reducing its Cr content to minimize susceptibility to irradiation-assisted α´ formation. The composition effects and critical limits to retaining protective scale formation at > 1400°C are still being evaluated.

  6. Evolution of the internal friction in SIC particle reinforced 8090 Al-Li metal matrix composite; Evolucion de la friccion interna del material compuesto de matriz Al-Li 8090 reforzado con particulas de SiC

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Urrutia, I.; Gallego, I.; No, M. L.; San Juan, J. M.

    2001-07-01

    The present study has been undertaken to investigate the mechanisms of thermal stress relief at the range of temperatures below room temperature for the metal matrix composite Al-Li 8090/SiC. For this aim the experimental technique of internal friction has been used which has been showed up very effective. Several thermal cycles from 453 K to 100 K were used in order to measures the internal friction as well as the elastic modules of the material concluding that thermal stresses are relaxed by microplastic deformation around the reinforcements. It has been also related the variation in the elastic modules with the different levels of precipitation. (Author) 18 refs.

  7. Initial Cladding Condition

    Energy Technology Data Exchange (ETDEWEB)

    E. Siegmann

    2000-08-22

    The purpose of this analysis is to describe the condition of commercial Zircaloy clad fuel as it is received at the Yucca Mountain Project (YMP) site. Most commercial nuclear fuel is encased in Zircaloy cladding. This analysis is developed to describe cladding degradation from the expected failure modes. This includes reactor operation impacts including incipient failures, potential degradation after reactor operation during spent fuel storage in pool and dry storage and impacts due to transportation. Degradation modes include cladding creep, and delayed hydride cracking during dry storage and transportation. Mechanical stresses from fuel handling and transportation vibrations are also included. This Analysis and Model Report (AMR) does not address any potential damage to assemblies that might occur at the YMP surface facilities. Ranges and uncertainties have been defined. This analysis will be the initial boundary condition for the analysis of cladding degradation inside the repository. In accordance with AP-2.13Q, ''Technical Product Development Planning'', a work plan (CRWMS M&O 2000c) was developed, issued, and utilized in the preparation of this document. There are constraints, caveats and limitations to this analysis. This cladding degradation analysis is based on commercial Pressurized Water Reactor (PWR) fuel with Zircaloy cladding but is applicable to Boiling Water Reactor (BWR) fuel. Reactor operating experience for both PWRs and BWRs is used to establish fuel reliability from reactor operation. It is limited to fuel exposed to normal operation and anticipated operational occurrences (i.e. events which are anticipated to occur within a reactor lifetime), and not to fuel that has been exposed to severe accidents. Fuel burnup projections have been limited to the current commercial reactor licensing environment with restrictions on fuel enrichment, oxide coating thickness and rod plenum pressures. The information provided in this analysis

  8. Ion irradiation testing of Improved Accident Tolerant Cladding Materials

    Energy Technology Data Exchange (ETDEWEB)

    Anderoglu, Osman [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tesmer, Joseph R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Maloy, Stuart A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-14

    This report summarizes the results of ion irradiations conducted on two FeCrAl alloys (named as ORNL A&B) for improving the accident tolerance of LWR nuclear fuel cladding. After irradiation with 1.5 MeV protons to ~0.5 to ~1 dpa and 300°C nanoindentations were performed on the cross-sections along the ion range. An increase in hardness was observed in both alloys. Microstructural analysis shows radiation induced defects.

  9. Review of experimental data for modelling LWR fuel cladding behaviour under loss of coolant accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Massih, Ali R. [Quantum Technologies AB, Uppsala Science Park (Sweden)

    2007-02-15

    Extensive range of experiments has been conducted in the past to quantitatively identify and understand the behaviour of fuel rod under loss-of-coolant accident (LOCA) conditions in light water reactors (LWRs). The obtained experimental data provide the basis for the current emergency core cooling system acceptance criteria under LOCA conditions for LWRs. The results of recent experiments indicate that the cladding alloy composition and high burnup effects influence LOCA acceptance criteria margins. In this report, we review some past important and recent experimental results. We first discuss the background to acceptance criteria for LOCA, namely, clad embrittlement phenomenology, clad embrittlement criteria (limitations on maximum clad oxidation and peak clad temperature) and the experimental bases for the criteria. Two broad kinds of test have been carried out under LOCA conditions: (i) Separate effect tests to study clad oxidation, clad deformation and rupture, and zirconium alloy allotropic phase transition during LOCA. (ii) Integral LOCA tests, in which the entire LOCA sequence is simulated on a single rod or a multi-rod array in a fuel bundle, in laboratory or in a tests and results are discussed and empirical correlations deduced from these tests and quantitative models are conferred. In particular, the impact of niobium in zirconium base clad and hydrogen content of the clad on allotropic phase transformation during LOCA and also the burst stress are discussed. We review some recent LOCA integral test results with emphasis on thermal shock tests. Finally, suggestions for modelling and further evaluation of certain experimental results are made.

  10. Analysis and optimization of process parameters in Al-SiCp laser cladding

    Science.gov (United States)

    Riquelme, Ainhoa; Rodrigo, Pilar; Escalera-Rodríguez, María Dolores; Rams, Joaquín

    2016-03-01

    The laser cladding process parameters have great effect on the clad geometry and on dilution in the single and multi-pass aluminum matrix composite reinforced with SiC particles (Al/SiCp) coatings on ZE41 magnesium alloys deposited using a high-power diode laser (HPLD). The influence of the laser power (500-700 W), scan speed (3-17 mm/s) and laser beam focal position (focus, positive and negative defocus) on the shape factor, cladding-bead geometry, cladding-bead microstructure (including the presence of pores and cracks), and hardness has been evaluated. The correlation of these process parameters and their influence on the properties and ultimately, on the feasibility of the cladding process, is demonstrated. The importance of focal position is demonstrated. The different energy distribution of the laser beam cross section in focus plane or in positive and negative defocus plane affect on the cladding-bead properties.

  11. Characterization of hard coatings produced by laser cladding using laser-induced breakdown spectroscopy technique

    Energy Technology Data Exchange (ETDEWEB)

    Varela, J.A.; Amado, J.M.; Tobar, M.J.; Mateo, M.P.; Yañez, A.; Nicolas, G., E-mail: gines@udc.es

    2015-05-01

    Highlights: • Chemical mapping and profiling by laser-induced breakdown spectroscopy (LIBS) of coatings produced by laser cladding. • Production of laser clads using tungsten carbide (WC) and nickel based matrix (NiCrBSi) powders. • Calibration by LIBS of hardfacing alloys with different WC concentrations. - Abstract: Protective coatings with a high abrasive wear resistance can be obtained from powders by laser cladding technique, in order to extend the service life of some industrial components. In this work, laser clad layers of self-fluxing NiCrBSi alloy powder mixed with WC powder have been produced on stainless steel substrates of austenitic type (AISI 304) in a first step and then chemically characterized by laser-induced breakdown spectroscopy (LIBS) technique. With the suitable laser processing parameters (mainly output power, beam scan speed and flow rate) and powders mixture proportions between WC ceramics and NiCrBSi alloys, dense pore free layers have been obtained on single tracks and on large areas with overlapped tracks. The results achieved by LIBS technique and applied for the first time to the analysis of laser clads provided the chemical composition of the tungsten carbides in metal alloy matrix. Different measurement modes (multiple point analyses, depth profiles and chemical maps) have been employed, demonstrating the usefulness of LIBS technique for the characterization of laser clads based on hardfacing alloys. The behavior of hardness can be explained by LIBS maps which evidenced the partial dilution of some WC spheres in the coating.

  12. EPRI fuel cladding integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Yang, R. [Electric Power Research Institute, Palo Alto, CA (United States)

    1997-01-01

    The objectives of the EPRI fuel program is to supplement the fuel vendor research to assure that utility economic and operational interests are met. To accomplish such objectives, EPRI has conducted research and development efforts to (1) reduce fuel failure rates and mitigate the impact of fuel failures on plant operation, (2) provide technology to extend burnup and reduce fuel cycle cost. The scope of R&D includes fuel and cladding. In this paper, only R&D related to cladding integrity will be covered. Specific areas aimed at improving fuel cladding integrity include: (1) Fuel Reliability Data Base; (2) Operational Guidance for Defective Fuel; (3) Impact of Water Chemistry on Cladding Integrity; (4) Cladding Corrosion Data and Model; (5) Cladding Mechanical Properties; and (6) Transient Fuel Cladding Response.

  13. A Eutectic Melting Study of Double Wall Cladding Tubes of FeCrAl and Zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Woojin; Son, Seongmin; Lee, You Ho; Lee, Jeong Ik; Ryu, Ho Jin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Jeong, Eun [Kyunghee University, Yongin (Korea, Republic of)

    2015-10-15

    The eutectic melting behavior of FeCrAl/Zircaloy-4 double wall cladding tubes was investigated by annealing at various temperatures ranging from 900 .deg. C to 1300 .deg. C. It was found that significant eutectic melting occurred after annealing at temperatures equal to or higher than 1150 .deg. C. It means that an additional diffusion barrier layer is necessary to limit the eutectic melting between FeCrAl and Zircaloy-4 alloy cladding tubes. Coating of FeCrAl layers on the Zr alloy cladding tube is being investigated for the development of accident tolerant fuel by exploiting of both the oxidation resistance of FeCrAl alloys and the neutronic advantages of Zr alloys. Coating of FeCrAl alloys on Zr alloy cladding tubes can be performed by various techniques including thermal spray, laser cladding, and co-extrusion. Son et al. also reported the fabrication of FeCrAl/Zr ally double wall cladding by the shrink fit method. For the double layered cladding tubes, the thermal expansion mismatch between the dissimilar materials, severe deformation or mechanical failure due to the evolution of thermal stresses can occur when there is a thermal cycling. In addition to the thermal stress problems, chemical compatibilities between the two different alloys should be investigated in order to check the stability and thermal margin of the double wall cladding at a high temperature. Generally, it is considered that Zr alloy cladding will maintain its mechanical integrity up to 1204 .deg. C (2200 .deg. F) to satisfy the acceptance criteria for emergency core cooling systems.

  14. 激光熔覆Mo2C-Co基合金的工艺参数对其组织的影响%Influence of processing parameters of laser clad Mo2C-Co-based alloy on its microstructure

    Institute of Scientific and Technical Information of China (English)

    樊丁; 李晓康; 张建斌

    2012-01-01

    Laser melt-clad Mo2C/Co-based alloy coating with w(Mo2C) = 20% was fabricated on the surface of 409L ferritic stainless steel by using 10 kW CO2 laser. The process of laser cladding with different processing parameters such as laser power and scanning speed was studied, and on the basis of it, the formability, dimensions, organization, and performance of melt-clad layer were observed and analyzed with SEM, EDS, XRD and microscopic hardness meter. The result indicated that the rational laser cladding parameters were as follows: P=3. 6 kW, v=8 mm/s, the microstructure of the coating was composed of planar, columnar crystals, and the dendrite, and the cladding coating was mainly composed of Mo2C particles, sub-eutectic γ-Co and eutectic carbides of Cr23C6 and Cr7C3. With Mo2C added into Co-based alloy, the size of solidification microstructure was decreased, the gains were refined, and microhard-ness of the coating was improved from 870 HV to 1400 HV.%利用10 kW的CO2激光器在409L铁素体不锈钢表面激光熔覆ω(Mo2C) =20%的Mo2C/Co基涂层,运用SEM、EDS、XRD及显微硬度仪观察和分析激光功率和扫描速度对熔覆层成型性、尺寸、组织及性能的影响.结果表明:激光熔覆合理的工艺参数为:P=3.6 kW,v=8 mm/s;钴基熔覆层组织由平面晶、柱状晶、树枝晶构成,熔覆层中物相主要为Mo2C颗粒、亚共晶γ-Co和共晶碳化物Cr23 C6、Cr7C3;由于Mo2C颗粒加入,凝固组织的晶粒尺寸减小、晶粒细化,涂层的显微硬度从870 HV提高至1 400 HV.

  15. NAK80模具钢表面激光熔覆Ni基碳化钨合金涂层的组织和性能%Microstructure and Properties of Laser Cladding Ni-based Tungsten Carbide Alloy Coating on NAK80 Mold Steel

    Institute of Scientific and Technical Information of China (English)

    程虎; 方志刚; 赵先锐; 戴晟; 高玉新

    2011-01-01

    The Ni-based tungsten carbide alloy coating was fabricated on NAK80 mold steel by laser cladding technology. The characteristic of microstructure, micro-hardness and the formation mechanics were examined. The resuits show that the metallurgical bonding is good between the cladding coating and the steel substrate, the microstructure of laser cladding coating is composed of fir-tree crystal Cr23C6, un-melted tungsten carbide granular crystal, y-Ni solid solution and NiCr, CrB2. The micro-hardness of laser cladding coating is considerably higher than the substrate, so the wear-resisting property of mold surface is improved to some extent.%采用激光熔覆技术,在NAK80模具钢表面制备了Ni基碳化钨合金涂层.研究了激光熔覆涂层的组织结构特点及形成规律,测试分析了其显微硬度的分布特征.结果表明:涂层与基体之间呈良好冶金结合,熔覆层组织主要由树枝晶CrC、未熔碳化钨颗粒相、γ-Ni固溶体及少量分布于固溶体中的NiCr和CrB相组成;涂层的硬度远高于NAK80模具钢基体,从一定程度上改善了模具表面的耐磨性能.

  16. Mechanical Property and Intergranular Corrosion Sensitivity of Zn-Free and Zn-Microalloyed Al-2.7Cu-1.7Li-0.3Mg Alloys

    Science.gov (United States)

    Li, Jin-feng; Xu, Long; Cai, Chao; Chen, Yong-lai; Zhang, Xu-hu; Zheng, Zi-qiao

    2014-11-01

    The influence of 0.72 pct Zn addition on the tensile properties of Al-2.7Cu-1.7Li-0.3Mg alloys was investigated. Their intergranular corrosion (IGC) dependence on aging [T6 type at 423 K (150 °C) and 448 K (175 °C) and T8 type at 423 K (150 °C)] time was studied. An IGC diagram associated with aging process was established. The addition of 0.72 pct Zn enhanced the strength of the Al-Li alloy with T6 type aging at 448 K (175 °C). With aging process, the corrosion mode of the T6-aged Al-Li alloys was changed in the following order: pitting and local IGC (initial aging stage), general IGC (underaging stage), local IGC (near peak-aging stage), and pitting (overaging stage) again. The IGC depth was increased first and then decreased with aging time extension. The corrosion potential change of grains and the microstructure variation were used to explain the IGC sensitivity of the Al-Li alloy with different tempers. Meanwhile, 0.72 pct Zn addition decreased the IGC sensitivity of the Al-Li alloy, especially the T6-aged Al-Li alloy.

  17. BISON Fuel Performance Analysis of FeCrAl cladding with updated properties

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, Nathan M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wirth, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-30

    In order to improve the accident tolerance of light water reactor (LWR) fuel, alternative cladding materials have been proposed to replace zirconium (Zr)-based alloys. Of these materials, there is a particular focus on iron-chromium-aluminum (FeCrAl) alloys due to much slower oxidation kinetics in high-temperature steam than Zr-alloys. This should decrease the energy release due to oxidation and allow the cladding to remain integral longer in the presence of high temperature steam, making accident mitigation more likely. As a continuation of the development for these alloys, suitability for normal operation must also be demonstrated. This research is focused on modeling the integral thermo-mechanical performance of FeCrAl-cladded fuel during normal reactor operation. Preliminary analysis has been performed to assess FeCrAl alloys (namely Alkrothal 720 and APMT) as a suitable fuel cladding replacement for Zr-alloys, using the MOOSE-based, finite-element fuel performance code BISON and the best available thermal-mechanical and irradiation-induced constitutive properties. These simulations identify the effects of the mechanical-stress and irradiation response of FeCrAl, and provide a comparison with Zr-alloys. In comparing these clad materials, fuel rods have been simulated for normal reactor operation and simple steady-state operation. Normal reactor operating conditions target the cladding performance over the rod lifetime (~4 cycles) for the highest-power rod in the highest-power fuel assembly under reactor power maneuvering. The power histories and axial temperature profiles input into BISON were generated from a neutronics study on full-core reactivity equivalence for FeCrAl using the 3D full core simulator NESTLE. Evolution of the FeCrAl cladding behavior over time is evaluated by using steady-state operating conditions such as a simple axial power profile, a constant cladding surface temperature, and a constant fuel power history. The fuel rod designs and

  18. BISON Fuel Performance Analysis of FeCrAl cladding with updated properties

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, Nathan M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wirth, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-30

    In order to improve the accident tolerance of light water reactor (LWR) fuel, alternative cladding materials have been proposed to replace zirconium (Zr)-based alloys. Of these materials, there is a particular focus on iron-chromium-aluminum (FeCrAl) alloys due to much slower oxidation kinetics in high-temperature steam than Zr-alloys. This should decrease the energy release due to oxidation and allow the cladding to remain integral longer in the presence of high temperature steam, making accident mitigation more likely. As a continuation of the development for these alloys, suitability for normal operation must also be demonstrated. This research is focused on modeling the integral thermo-mechanical performance of FeCrAl cladded fuel during normal reactor operation. Preliminary analysis has been performed to assess FeCrAl alloys (namely Alkrothal 720 and APMT) as a suitable fuel cladding replacement for Zr-alloys, using the MOOSE-based, finite-element fuel performance code BISON and the best available thermal-mechanical and irradiation-induced constitutive properties. These simulations identify the effects of the mechanical-stress and irradiation response of FeCrAl and provide a comparison with Zr-alloys. In comparing these clad materials, fuel rods have been simulated for normal reactor operation and simple steady-state operation. Normal reactor operating conditions target the cladding performance over the rod lifetime (~4 cycles) for the highest-power rod in the highest-power fuel assembly under reactor power maneuvering. The power histories and axial temperature profiles input into BISON were generated from a neutronics study on full-core reactivity equivalence for FeCrAl using the 3D full core simulator NESTLE. Evolution of the FeCrAl cladding behavior over time is evaluated by using steady-state operating conditions such as a simple axial power profile, a constant cladding surface temperature, and a constant fuel power history. The fuel rod designs and

  19. Estimation of isothermal sections of ternary phase diagrams of lithium containing systems: the Al--Li--Mg system

    Energy Technology Data Exchange (ETDEWEB)

    Saboungi, M. L.; Hsu, C. C.

    1976-12-01

    The method of Kaufman and coworkers is used to provide an estimate of isothermal sections of the Al--Li--Mg system. One starts by calculating the lattice stability of the constituents, the binary interaction coefficients and the binary compound parameters. In the computations, thermodynamic data, when available, were coupled with measured phase diagrams to provide thermodynamically self-consistent liquidus and solidus curves for the binary systems. Standard enthalpies of formation and entropies of formation were calculated for the reported compounds. The binary system Li--Mg illustrates the use of such calculations in selecting the most reliable representation of the phase diagram. The calculated binary data were used to compute the phase diagram of Li--Al--Mg, assuming that no ternary compounds exist. 4 tables, 7 figures, 29 references. (GHT)

  20. Fuel pin cladding

    Science.gov (United States)

    Vaidyanathan, Swaminathan; Adamson, Martyn G.

    1986-01-01

    An improved fuel pin cladding, particularly adapted for use in breeder reactors, consisting of composite tubing with austenitic steel on the outer portion of the thickness of the tube wall and with nickel and/or ferritic material on the inner portion of the thickness of the tube wall. The nickel forms a sacrificial barrier as it reacts with certain fission products thereby reducing fission product activity at the austenitic steel interface. The ferritic material forms a preventive barrier for the austenitic steel as it is immune to liquid metal embrittlement. The improved cladding permits the use of high density fuel which in turn leads to a better breeding ratio in breeder reactors, and will increase the threshold at which failure occurs during temperature transients.

  1. Pulsed plasma arc cladding

    Institute of Scientific and Technical Information of China (English)

    龙; 白钢; 李振民; 张赋升; 杨思乾

    2004-01-01

    A prototype of Pulsed Plasma Arc Cladding system was developed, in which single power source supplies both transferred plasma arc (TPA) and non-transferred plasma arc (N-TPA). Both plasmas work in turn in a high frequency controlled by an IGBT connecting nozzle and workpiece. The working frequency of IGBT ranges from 50 ~ 7000Hz, in which the plasmas can work in turn smoothly. Higher than 500 Hz of working frequency is suggested for promotion of cladding quality and protection of IGBT. Drag phenomenon of TPA intensifies as the frequency goes up, which tends to increase the current proportion of TPA and suppress N-TPA. The occupation ratio of IGBT can be regulated from 5% ~ 95%, which balances the power supplies of both plasmas. An occupation ratio higher than 50% gives adequate proportion of arc current for N-TPA to preheat powder.

  2. Electrochemical profiling of multi-clad aluminium sheets used in automotive heat exchangers

    DEFF Research Database (Denmark)

    Bordo, Kirill; Ambat, Rajan; Peguet, Lionel;

    2014-01-01

    The objective of the present study is to understand the mechanisms of corrosion propagation across the multi-clad structure of Al alloys sheets as a function of local alloy composition and microstructure, with and without brazing treatment. Electro-chemical behaviour at different depths was profi...

  3. Microstructure and wear studies of laser clad Al-Si/SiC(p) composite coatings

    NARCIS (Netherlands)

    Anandkumar, R.; Almeida, A.; Colaco, R.; Vilar, R.; Ocelik, V.; De Hosson, J. Th. M.

    2007-01-01

    Coatings of a composite material consisting of an Al-Si matrix reinforced with SiC particles were produced by laser cladding on UNS A03560 cast Al-alloy substrates from mixtures of powders of Al-12 wt.% Si alloy and SiC. The influence of the processing parameters on the microstructure and abrasive w

  4. Laser cladding of Al-Si/SiC composite coatings : Microstructure and abrasive wear behavior

    NARCIS (Netherlands)

    Anandkumar, R.; Almeida, A.; Vilar, R.; Ocelik, V.; De Hosson, J.Th.M.

    2007-01-01

    Surface coatings of an Al-Si-SiC composite were produced on UNS A03560 cast Al-alloy substrates by laser cladding using a mixture of powders of Al-12 wt.% Si alloy and SiC. The microstructure of the coatings depends considerably on the processing parameters. For a specific energy of 26 MJ/m2 the mic

  5. Madelung energy for random metallic alloys in the coherent potential approximation

    DEFF Research Database (Denmark)

    Korzhavyi, P. A.; Ruban, Andrei; Abrikosov, I. A.;

    1995-01-01

    one to include charge-transfer effects in the framework of the CPA. We show how the models work in actual calculations for selected metallic alloy systems, Al-Li, Li-Mg, and Ni-Pt, which exhibit charge transfer. We find that the so-called screened impurity model (β=1), which is derived completely...... within the mean-field single-site approximation, leads to the best agreement with experimental lattice parameter and mixing energy data for Al-Li and Li-Mg alloys. However, for the Ni-Pt system exhibiting strong ordering tendency this model seems to overestimate the Madelung energy of the completely...

  6. Mitigating Abnormal Grain Growth for Friction Stir Welded Al-Li 2195 Spun Formed Domes

    Science.gov (United States)

    Chen, Po-Shou; Russell, Carolyn

    2012-01-01

    Formability and abnormal grain growth (AGG) are the two major issues that have been encountered for Al alloy spun formed dome development using friction stir welded blanks. Material properties that have significant influence on the formability include forming range and strain hardening exponent. In this study, tensile tests were performed for two 2195 friction stir weld parameter sets at 400 F to study the effects of post weld anneal on the forming range and strain hardening exponent. It was found that the formability can be enhanced by applying a newly developed post weld anneal to heat treat the friction stir welded panels. This new post weld anneal leads to a higher forming range and much improved strain hardening exponent. AGG in the weld nugget is known to cause a significant reduction of ductility and fracture toughness. This study also investigated how AGG may be influenced by the heating rate to the solution heat treatment temperature. After post-weld annealing, friction stir welds were strained to 15% and 39% by compression at 400 F before they were subjected to SHT at 950 F for 1 hour. Salt bath SHT is very effective in reducing the grain size as it helps arrest the onset of AGG and promote normal recrystallization and grain growth. However, heat treating a 18 ft dome using a salt bath is not practical. Efforts are continuing at Marshall Space Flight Center to identify the welding parameters and heat treating parameters that can help mitigate the AGG in the friction stir welds.

  7. Results of NDE Technique Evaluation of Clad Hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Kunerth, Dennis C. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    This report fulfills the M4 milestone, M4FT-14IN0805023, Results of NDE Technique Evaluation of Clad Hydrides, under Work Package Number FT-14IN080502. During service, zirconium alloy fuel cladding will degrade via corrosion/oxidation. Hydrogen, a byproduct of the oxidation process, will be absorbed into the cladding and eventually form hydrides due to low hydrogen solubility limits. The hydride phase is detrimental to the mechanical properties of the cladding and therefore it is important to be able to detect and characterize the presence of this constituent within the cladding. Presently, hydrides are evaluated using destructive examination. If nondestructive evaluation techniques can be used to detect and characterize the hydrides, the potential exists to significantly increase test sample coverage while reducing evaluation time and cost. To demonstrate the viability this approach, an initial evaluation of eddy current and ultrasonic techniques were performed to demonstrate the basic ability to these techniques to detect hydrides or their effects on the microstructure. Conventional continuous wave eddy current techniques were applied to zirconium based cladding test samples thermally processed with hydrogen gas to promote the absorption of hydrogen and subsequent formation of hydrides. The results of the evaluation demonstrate that eddy current inspection approaches have the potential to detect both the physical damage induced by hydrides, e.g. blisters and cracking, as well as the combined effects of absorbed hydrogen and hydride precipitates on the electrical properties of the zirconium alloy. Similarly, measurements of ultrasonic wave velocities indicate changes in the elastic properties resulting from the combined effects of absorbed hydrogen and hydride precipitates as well as changes in geometry in regions of severe degradation. However, for both approaches, the signal responses intended to make the desired measurement incorporate a number of contributing

  8. Recent developments of the aluminium-lithium system alloys for aircraft uses; Recentes desenvolvimentos das ligas do sistema aluminio-litio para fins aeronauticos

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Marcelo; Plaut, Ronald Lesley

    1992-12-31

    A brief review is made of the latest developments in the production of Aluminium-Lithium alloys. The necessity for new materials in the field of aeronautics has speeded up research on metallic and non-metallic materials. Lately, a good part of the research in the field of metallic components has been directed at Al-Li alloys. More recently, with the development of quaternary alloys Al-Li-X-X, the old problem of low toughness was overcome. The finality of this study is to cover the developments of the mentioned alloys, including the fundamentals of physical metallurgy of the complex system recently developed Al-Li-Cu-Mg. (author) 27 refs., 2 figs., 4 tabs.

  9. Wear resistance of laser cladding and plasma spray welding layer on stainless steel surface

    Institute of Scientific and Technical Information of China (English)

    Xinlin Wang(王新林); Shihong Shi(石世宏); Qiguang Zheng(郑启光)

    2004-01-01

    The effect of coatings, which are formed with laser cladding and plasma spray welding on 1Cr18Ni9Ti base metal, on wear resistance is studied, A 5-kW transverse flowing CO2 laser is used for cladding Co base alloy powder pre-placed on the substrate. Comparing with the plasma spray coatings, the spoiled rate of products with laser clad layers was lower and the rate of finished products was higher. Their microstructure is extremely fine. They have close texture and small size grain. Their dilution resulting from the compositions of the base metal and thermal effect on base metal are less. The hardness, toughness,and strength of the laser cladding layers are higher. Wear tests show that the laser layers have higher properties of anti-friction, anti-scour and high-temperature sliding strike. The wear resistance of laser clad layers are about one time higher than that of plasma spray welding layer.

  10. Sensitivity analysis of a PWR fuel element using zircaloy and silicon carbide claddings

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Rochkhudson B. de; Cardoso, Fabiano; Salome, Jean A.D.; Pereira, Claubia; Fortini, Angela, E-mail: rochkhudson@ufmg.br, E-mail: claubia@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Departamento de Engenharia Nuclear

    2015-07-01

    The alloy composed of zirconium has been used effectively for over 50 years in claddings of nuclear fuel, especially for PWR type reactors. However, to increase fuel enrichment with the aim of raising the burning and maintaining the safety of nuclear plants is of great relevance the study of new materials that can replace safely and efficiently zircaloy cladding. Among several proposed material, silicon carbide (SiC) has a potential to replace zircaloy as fuel cladding material due to its high-temperature tolerance, chemical stability and low neutron affinity. In this paper, the goal is to expand the study with silicon carbide cladding, checking its behavior when submitted to an environment with boron, burnable poison rods, and temperature variations. Sensitivity calculation and the impact in multiplication factor to both claddings, zircaloy and silicon carbide, were performed during the burnup. The neutronic analysis was made using the SCALE 6.0 (Standardized Computer Analysis for Licensing Evaluation) code. (author)

  11. Synthesis of Y2O3 particle enhanced Ni/TiC composite on TC4 Ti alloy by laser cladding%TC4钛合金表面激光熔覆法制备Y2O3颗粒增强Ni/TiC复合涂层

    Institute of Scientific and Technical Information of China (English)

    张可敏; 邹建新; 李军; 于治水; 王慧萍

    2012-01-01

    A Y2O3 particle enhanced Ni/TiC composite coating was fabricated in-situ on a TC4 Ti alloy by laser surface cladding.The phase component,microstructure,composition distribution and properties of the composite layer were investigated.The composite layer has graded microstructures and compositions,due to the fast melting followed by rapid solidification and cooling during laser cladding.The TiC powders are completely dissolved into the melted layer during melting and segregated as fine dendrites when solidified.The size of TiC dendrites decreases with increasing depth.Y2O3 fine particles distribute in the whole clad layer.The Y2O3 particle enhanced Ni/TiC composite layer has a quite uniform hardness along depth with a maximum value of HV1380,which is 4 times higher than the initial hardness.The wear resistance of the Ti alloy is significantly improved after laser cladding due to the high hardness of the composite coating.%采用激光熔覆法在TC4钛合金表面原位制备Y2O3颗粒增强Ni/TiC复合涂层,研究涂层的相组成、微结构、成分分布及性能.结果表明,复合涂层内的微结构和成分在深度方向具有分层现象,这主要是由激光熔覆过程的快速熔凝和冷却过程所致.在激光熔覆过程中,TiC粉末完全熔化并在凝固过程中析出为细小枝晶,这些TiC枝晶的尺寸随着深度的增加而减小,而Y2O3颗粒则分布在整个重熔层中.Y2O3颗粒增强Ni/TiC复合涂层具有较均匀的硬度,其最高值约为HV1380,比基体高4倍以上.由于复合涂层具有高的硬度,钛合金经过激光熔覆后其耐磨性得到大幅度提高.

  12. Alloy

    Science.gov (United States)

    Cabeza, Sandra; Garcés, Gerardo; Pérez, Pablo; Adeva, Paloma

    2014-07-01

    The Mg98.5Gd1Zn0.5 alloy produced by a powder metallurgy route was studied and compared with the same alloy produced by extrusion of ingots. Atomized powders were cold compacted and extruded at 623 K and 673 K (350 °C and 400 °C). The microstructure of extruded materials was characterized by α-Mg grains, and Mg3Gd and 14H-LPSO particles located at grain boundaries. Grain size decreased from 6.8 μm in the extruded ingot, down to 1.6 μm for powders extruded at 623 K (350 °C). Grain refinement resulted in an increase in mechanical properties at room and high temperatures. Moreover, at high temperatures the PM alloy showed superplasticity at high strain rates, with elongations to failure up to 700 pct.

  13. Improved LWR Cladding Performance by EPD Surface Modification Technique

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Michael; Sridharan, Kumar

    2012-11-26

    This project will utilize the electro-phoretic deposition technique (EPD) in conjunction with nanofluids to deposit oxide coatings on prototypic zirconium alloy cladding surfaces. After demonstrating that this surface modification is reproducible and robust, the team will subject the modified surface to boiling and corrosion tests to characterize the improved nucleate boiling behavior and superior corrosion performance. The scope of work consists of the following three tasks: The first task will employ the EPD surface modification technique to coat the surface of a prototypic set of zirconium alloy cladding tube materials (e.g. Zircaloy and advanced alloys such as M5) with a micron-thick layer of zirconium oxide nanoparticles. The team will characterize the modified surface for uniformity using optical microscopy and scanning-electron microscopy, and for robustness using standard hardness measurements. After zirconium alloy cladding samples have been prepared and characterized using the EPD technique, the team will begin a set of boiling experiments to measure the heat transfer coefficient and critical heat flux (CHF) limit for each prepared sample and its control sample. This work will provide a relative comparison of the heat transfer performance for each alloy and the surface modification technique employed. As the boiling heat transfer experiments begin, the team will also begin corrosion tests for these zirconium alloy samples using a water corrosion test loop that can mimic light water reactor (LWR) operational environments. They will perform extended corrosion tests on the surface-modified zirconium alloy samples and control samples to examine the robustness of the modified surface, as well as the effect on surface oxidation

  14. Development of powder metallurgy Al alloys for high temperature aircraft structural applications, phase 2

    Science.gov (United States)

    Chellman, D. J.

    1982-01-01

    In this continuing study, the development of mechanically alloyed heat resistant aluminum alloys for aircraft were studied to develop higher strength targets and higher service temperatures. The use of higher alloy additions to MA Al-Fe-Co alloys, employment of prealloyed starting materials, and higher extrusion temperatures were investigated. While the MA Al-Fe-Co alloys exhibited good retention of strength and ductility properties at elevated temperatures and excellent stability of properties after 1000 hour exposure at elevated temperatures, a sensitivity of this system to low extrusion strain rates adversely affected the level of strength achieved. MA alloys in the Al-Li family showed excellent notched toughness and property stability after long time exposures at elevated temperatures. A loss of Li during processing and the higher extrusion temperature 482 K (900 F) resulted in low mechanical strengths. Subsequent hot and cold working of the MA Al-Li had only a mild influence on properties.

  15. Aerogel-clad optical fiber

    Science.gov (United States)

    Sprehn, Gregory A.; Hrubesh, Lawrence W.; Poco, John F.; Sandler, Pamela H.

    1997-01-01

    An optical fiber is surrounded by an aerogel cladding. For a low density aerogel, the index of refraction of the aerogel is close to that of air, which provides a high numerical aperture to the optical fiber. Due to the high numerical aperture, the aerogel clad optical fiber has improved light collection efficiency.

  16. Pulsed Magnetic Welding for Advanced Core and Cladding Steel

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Guoping [Univ. of Wisconsin, Madison, WI (United States); Yang, Yong [Univ. of Florida, Gainesville, FL (United States)

    2013-12-19

    To investigate a solid-state joining method, pulsed magnetic welding (PMW), for welding the advanced core and cladding steels to be used in Generation IV systems, with a specific application for fuel pin end-plug welding. As another alternative solid state welding technique, pulsed magnetic welding (PMW) has not been extensively explored on the advanced steels. The resultant weld can be free from microstructure defects (pores, non-metallic inclusions, segregation of alloying elements). More specifically, the following objectives are to be achieved: 1. To design a suitable welding apparatus fixture, and optimize welding parameters for repeatable and acceptable joining of the fuel pin end-plug. The welding will be evaluated using tensile tests for lap joint weldments and helium leak tests for the fuel pin end-plug; 2 Investigate the microstructural and mechanical properties changes in PMW weldments of proposed advanced core and cladding alloys; 3. Simulate the irradiation effects on the PWM weldments using ion irradiation.

  17. Oxidation resistant chromium coating on Zircaloy-4 for accident tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung-Hwan; Kim, Eui-Jung; Jung, Yang-Il; Park, Dong-Jun; Kim, Hyun-Gil; Park, Jeong-Yong; Koo, Yang-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The attributes of such a fuel are approved reaction kinetics with steam, a slower hydrogen generation rate, and good cladding thermo-mechanical properties. Many researchers have tried to modify zirconium alloys to improve their oxidation resistance in the early stages of the ATF development. Corrosion resistant coating on cladding is one of the candidate technologies to improve the oxidation resistance of zirconium cladding. By applying coating technology to zirconium cladding, it is easy to obtain corrosion resistance without a change in the base materials. Among the surface coating methods, arc ion plating (AIP) is a coating technology to improve the adhesion owing to good throwing power, and a dense deposit (Fig. 1). Owing to these advantages, AIP has been widely used to efficiently form protective coatings on cutting tools, dies, bearings, etc. In this study, The AIP technique for the protection of zirconium claddings from the oxidation in a high-temperature steam environment was studied. The homogeneous Cr film with a high adhesive ability to the cladding was deposited by AIP and acted as a protection layer to enhance the corrosion resistance of the zirconium cladding. It was concluded that the AIP technology is effective for coating a protective layer on claddings.

  18. Stone cladding engineering

    CERN Document Server

    Sousa Camposinhos, Rui de

    2014-01-01

    This volume presents new methodologies for the design of dimension stone based on the concepts of structural design while preserving the excellence of stonemasonry practice in façade engineering. Straightforward formulae are provided for computing action on cladding, with special emphasis on the effect of seismic forces, including an extensive general methodology applied to non-structural elements. Based on the Load and Resistance Factor Design Format (LRDF), minimum slab thickness formulae are presented that take into consideration stress concentrations analysis based on the Finite Element Method (FEM) for the most commonly used modern anchorage systems. Calculation examples allow designers to solve several anchorage engineering problems in a detailed and objective manner, underlining the key parameters. The design of the anchorage metal parts, either in stainless steel or aluminum, is also presented.

  19. Reactivity Initiated Accident Simulation to Inform Transient Testing of Candidate Advanced Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Nicholas R [ORNL; Wysocki, Aaron J [ORNL; Terrani, Kurt A [ORNL

    2016-01-01

    Abstract. Advanced cladding materials with potentially enhanced accident tolerance will yield different light water reactor performance and safety characteristics than the present zirconium-based cladding alloys. These differences are due to different cladding material properties and responses to the transient, and to some extent, reactor physics, thermal, and hydraulic characteristics. Some of the differences in reactors physics characteristics will be driven by the fundamental properties (e.g., absorption in iron for an iron-based cladding) and others will be driven by design modifications necessitated by the candidate cladding materials (e.g., a larger fuel pellet to compensate for parasitic absorption). Potential changes in thermal hydraulic limits after transition from the current zirconium-based cladding to the advanced materials will also affect the transient response of the integral fuel. This paper leverages three-dimensional reactor core simulation capabilities to inform on appropriate experimental test conditions for candidate advanced cladding materials in a control rod ejection event. These test conditions are using three-dimensional nodal kinetics simulations of a reactivity initiated accident (RIA) in a representative state-of-the-art pressurized water reactor with both nuclear-grade iron-chromium-aluminum (FeCrAl) and silicon carbide based (SiC-SiC) cladding materials. The effort yields boundary conditions for experimental mechanical tests, specifically peak cladding strain during the power pulse following the rod ejection. The impact of candidate cladding materials on the reactor kinetics behavior of RIA progression versus reference zirconium cladding is predominantly due to differences in: (1) fuel mass/volume/specific power density, (2) spectral effects due to parasitic neutron absorption, (3) control rod worth due to hardened (or softened) spectrum, and (4) initial conditions due to power peaking and neutron transport cross sections in the

  20. Friction surface cladding: development of a solid state cladding process

    NARCIS (Netherlands)

    Stelt, van der Adrianus Anton

    2014-01-01

    Many industries including automotive, aerospace, electronics, shipbuilding, offshore, railway and heavy equipment employ surface modification technologies to change the surface properties of a manufactured product. Often, the surface is covered (coated) with a dissimilar clad layer for this purpose

  1. Análisis del Comportamiento Mecánico de Recargues de Inoxidable Sobre Acero de Baja Aleación en Reactores de Proceso Analysis of Mechanical Behavior of Cladding of Stainless Steel over Low Alloyed Steel in Process Reactors

    Directory of Open Access Journals (Sweden)

    B.Y. Moratilla

    2005-01-01

    Full Text Available Se realiza un estudio simple de tensiones considerando dos materiales, acero inoxidable y acero de baja aleación. El estudio es motivado porque en la industria petroquímica es práctica habitual, para reducir costes de materiales, utilizar recargues de inoxidable sobre una pared de acero de baja aleación para la construcción de la pared de reactores. Se determina el coeficiente de dilatación térmica y su evolución a lo largo del espesor de la zona afectada térmicamente, usando una probeta extraída durante la construcción de un reactor. Luego se aplican los resultados obtenidos a un modelo de la pared del reactor usando el método de los elementos finitos. Los resultados muestran que el uso del recargue está científica y tecnológicamente justificado.A simple study of tensions was carried out on stainless steel and low alloyed steel. The reason for the study was that a typical practice in the petrochemical industry for materials cost reduction is the use of layers of stainless steel cladding over low alloy steel in the construction of reactor walls. The coefficient of thermal dilatation and its' evolution throughout the thickness of the thermally affected zone was determined using a test sample obtained during the construction of a reactor. Later, the results obtained were applied to a model of the reactor wall using the finite element method. The results suggested that the use of the cladding was scientifically and technologically justified.

  2. Weld overlay cladding with iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, G.M. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    The hot and cold cracking tendencies of some early iron aluminide alloy compositions have limited their use in applications where good weldability is required. Using hot crack testing techniques invented at ORNL, and experimental determinations of preheat and postweld heat treatment needed to avoid cold cracking, we have developed iron aluminide filler metal compositions which can be successfully used to weld overlay clad various substrate materials, including 9Cr-1Mo steel, 2-1/4Cr-1Mo steel, and 300-series austenitic stainless steels. Dilution must be carefully controlled to avoid crack-sensitive deposit compositions. The technique used to produce the current filler metal compositions is aspiration-casting, i.e. drawing the liquid from the melt into glass rods. Future development efforts will involve fabrication of composite wires of similar compositions to permit mechanized gas tungsten arc (GTA) and/or gas metal arc (GMA) welding.

  3. 塑料模具钢表面激光熔覆WxC/Ni基合金涂层的组织及性能%Microstructure and properties of laser clad Ni-based tungsten carbide alloy layer on a plastic mould steel

    Institute of Scientific and Technical Information of China (English)

    赵先锐; 左敦稳; 程虎; 李勤涛; 戴晟; 冯尚申

    2013-01-01

    采用TJ-HL-5000横流CO2连续激光器在2738塑料模具钢表面制备了WxC/Ni基合金涂层.利用金相显微镜、SEM、EDS、XRD、显微硬度计以及摩擦磨损试验机等检测设备研究了激光熔覆涂层组织及性能.XRD分析结果表明,熔覆层的主要物相有γ-Ni、W2C、WC、M23C6(M=Cr,Ni,Mo,W)、NiCr和Cr2O3等.金相显微镜、SEM和EDS分析结果表明,结合区为良好冶金结合,结合区为FeNiCrW合金,厚度为20 μm左右;基体对熔覆层合金的稀释度很低;熔覆层从界面向外依次分布着平面晶区、细等轴晶区、粗树枝晶区以及表面细晶区.显微硬度计结果表明,熔覆层的硬度值平均约900 HV1,是基体硬度的2.8倍左右.摩擦磨损试验结果表明,与基体相比熔覆层的耐磨性有了很大提高.%The WxC /Ni-based alloy layer was successfully coated onto 2738 plastic mould steel surface by using a TJ-HL-5000 transverse-flow CO2 continuous laser. Microstructure and mechanical properties of the coatings were investigated by metallographic microscope, SEM/ EDS, XRD, Vickers microhardness tester and friction-abrasion testing machine. XRD results show that the clad layer consists of WC, γ-nickel, Ni4B3, Cr7C3, W2C, M23 C6 ( M = Cr, Ni, Mo, W), NiCr and Cr2O3 phases. SEM and EDS results indicate that the metallurgical bonding is formed between the cladding coating and the steel substrate, and the interface zone is FeNiCrW alloy with thickness of 20 μm or so. From the interface to surface, the clad coatings consist of plane crystal layer, fine equiaxial crystal layer, coarse dendrite layer and surface fine-grain layer. The results of Vickers microhardness tesing show that the average micro-hardness of the laser clad coating is about 900 HV1, which is 1. 8 times higher than that of the steel substrate. The results of friction-wear test indicate that the wear resistance of the steel with clad layer is improved significantly compared with the substrate.

  4. Technical basis for storage of Zircaloy-clad spent fuel in inert gases

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B. Jr.; Gilbert, E.R.

    1983-09-01

    This report summarizes the technical bases to establish safe conditions for dry storage of Zircaloy-clad fuel. Dry storage of fuel with zirconium alloy cladding has been licensed in Canada, the Federal Republic of Germany, and Switzerland. In addition, dry storage demonstrations, hot cell tests, and modeling have been conducted using Zircaloy-clad fuel. The demonstrations have included irradiated boiling water reactor, pressurized heavy-water reactor, and pressurized water reactor (PWR) fuel assemblies. Irradiated fuel has been emplaced in and retrieved from metal casks, dry wells, silos, and a vault. Dry storage tests and demonstrations have involved {similar_to}5,000 fuel rods, and {similar_to}600 rods have been monitored during dry storage in inert gases with maximum cladding temperatures ranging from 50 to 570{sup 0}C. Although some tests and demonstrations are still in progress, there is currently no evidence that any rods exposed to inert gases have failed (one PWR rod exposed to an air cover gas failed at {similar_to}70{sup 0}C). Based on this favorable experience, it is concluded that there is sufficient information on fuel rod behavior, storage conditions, and potential cladding failure mechanisms to support licensing of dry storage in the United States. This licensing position includes a requirement for inert cover gases and a maximum cladding temperature guideline of 380{sup 0}C for Zircaloy-clad fuel. Using an inert cover gas assures that even if fuel with cladding defects were placed in dry storage, or if defects develop during storage, the defects would not propagate. Tests and demonstrations involving Zircaloy-clad rods and assemblies with maximum cladding temperatures above 400{sup 0}C are in progress. When the results from these tests have been evaluated, the viability of higher temperature limits should be examined. Acceptable conditions for storage in air and dry storage of consolidated fuel are issues yet to be resolved.

  5. Experimental Study on Surface Characteristics of Laser Cladding Layer Regulated by High-Frequency Microforging

    Science.gov (United States)

    Fan, Xiang Fang; Zhou, Ju; Qiu, Chang Jun; He, Bin; Ye, Jiang; Yuan, Bo; Pi, Zhengqing

    2011-03-01

    High-frequency microforging technology is used to produce micrometer-scale plastic deformation on the surface of material out of the vibration impact of a forging punch, and the cumulative effect of its various frequencies on micrometer-scale plastic deformation can cause changes of surface microstructure and mechanical properties. This study used (1) a self-made machine to treat NiCrBSi alloy, (2) a mechanical comparator and optical microscopy (OM) to study the geometric characteristics of plastic deformation, (3) OM and scanning electric microscopy (SEM) to observe influence on surface microstructure and cracking behavior of the laser cladding layer under microforging, (4) x-ray diffractometer (XRD) to measure the surface residual stress of laser cladding layer before and after forging, and (5) microhardness tester and wearing experimental machine to study changes of microhardness, friction coefficient, and wear characteristics of laser cladding layer after microforging. The results have shown that high-frequency microforging could produce plastic deformation about 150 μm deep on the surface of NiCrBSi alloy clad by laser. Regular dendrite and eutectic crystallization microstructure, which is a peculiar characteristic of the laser cladding layer, was broken into pieces and formed residual compression residual stress on the surface. Resistance to cracking of laser cladding layer improved greatly, microhardness and wearability increased, and the friction coefficient did not under go a noticeable change.

  6. Crack resistance curves determination of tube cladding material

    Science.gov (United States)

    Bertsch, J.; Hoffelner, W.

    2006-06-01

    Zirconium based alloys have been in use as fuel cladding material in light water reactors since many years. As claddings change their mechanical properties during service, it is essential for the assessment of mechanical integrity to provide parameters for potential rupture behaviour. Usually, fracture mechanics parameters like the fracture toughness KIC or, for high plastic strains, the J-integral based elastic-plastic fracture toughness JIC are employed. In claddings with a very small wall thickness the determination of toughness needs the extension of the J-concept beyond limits of standards. In the paper a new method based on the traditional J approach is presented. Crack resistance curves (J-R curves) were created for unirradiated thin walled Zircaloy-4 and aluminium cladding tube pieces at room temperature using the single sample method. The procedure of creating sharp fatigue starter cracks with respect to optical recording was optimized. It is shown that the chosen test method is appropriate for the determination of complete J-R curves including the values J0.2 (J at 0.2 mm crack length), Jm (J corresponding to the maximum load) and the slope of the curve.

  7. Optimization of Hydride Rim Formation in Unirradiated Zr 4 Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Hanson, Brady D.; MacFarlan, Paul J.

    2013-09-30

    The purpose of this work is to build on the results reported in the M2 milestone M2FT 13PN0805051, document number FCRD-USED-2013-000151 (Hanson, 2013). In that work, it was demonstrated that unirradiated samples of zircaloy-4 cladding could be pre-hydrided at temperatures below 400°C in pure hydrogen gas and that the growth of hydrides on the surface could be controlled by changing the surface condition of the samples and form a desired hydride rim on the outside diameter of the cladding. The work performed at Pacific Northwest National Laboratory since the issuing of the M2 milestone has focused its efforts to optimize the formation of a hydride rim on available zircaloy-4 cladding samples by controlling temperature variation and gas flow control during pre-hydriding treatments. Surface conditioning of the outside surface was also examined as a variable. The results of test indicate that much of the variability in the hydride thickness is due to temperature variation occurring in the furnaces as well as how hydrogen gas flows across the sample surface. Efforts to examine other alloys, gas concentrations, and different surface conditioning plan to be pursed in the next FY as more cladding samples become available

  8. Effect of Temperature and Sheet Temper on Isothermal Solidification Kinetics in Clad Aluminum Brazing Sheet

    Science.gov (United States)

    Benoit, Michael J.; Whitney, Mark A.; Wells, Mary A.; Winkler, Sooky

    2016-09-01

    Isothermal solidification (IS) is a phenomenon observed in clad aluminum brazing sheets, wherein the amount of liquid clad metal is reduced by penetration of the liquid clad into the core. The objective of the current investigation is to quantify the rate of IS through the use of a previously derived parameter, the Interface Rate Constant (IRC). The effect of peak temperature and initial sheet temper on IS kinetics were investigated. The results demonstrated that IS is due to the diffusion of silicon (Si) from the liquid clad layer into the solid core. Reduced amounts of liquid clad at long liquid duration times, a roughened sheet surface, and differences in resolidified clad layer morphology between sheet tempers were observed. Increased IS kinetics were predicted at higher temperatures by an IRC model as well as by experimentally determined IRC values; however, the magnitudes of these values are not in good agreement due to deficiencies in the model when applied to alloys. IS kinetics were found to be higher for sheets in the fully annealed condition when compared with work-hardened sheets, due to the influence of core grain boundaries providing high diffusivity pathways for Si diffusion, resulting in more rapid liquid clad penetration.

  9. Protection of spent aluminum-clad research reactor fuels during extended wet storage

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Stela M.C.; Correa, Olandir V.; Souza, Jose A.; Ramanathan, Lalgudi V., E-mail: lalgudi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Antunes, Renato A. [Universidade Federal do ABC (CECS/UFABC), Santo Andre, SP (Brazil). Centro de Engenharia, Modelagem e Ciencias Sociais; Ramanathan, Lalgudi V. [Electrocell Ind. Com. Equip. Elet. LTDA (CIETEC), Sao Paulo, SP (Brazil)

    2013-07-01

    Aluminum-clad spent nuclear fuel from research reactors (RR) is stored in light water filled pools or basins worldwide. Many incidences of pitting corrosion of the fuel cladding has been reported and attributed to synergism in the effect of certain water parameters. Protection of spent Al-clad RR fuel with a conversion coating was proposed in 2008. Preliminary results revealed increased pitting corrosion resistance of cerium oxide coated aluminum alloys AA 1050 and AA 6061, used as RR fuel plate cladding. Further development of conversion coatings for Al alloys was carried out and this paper presents: (a) the preparation and characterization of hydrotalcite (HTC) coatings; (b) the results of laboratory tests in which the corrosion behavior of coated Al alloys in NaCl solutions was determined; (c) the results of field tests in which un-coated, boehmite coated, HTC coated and cerium modified boehmite / HTC coated AA 1050 and AA 6061 coupons were exposed to the IEA-R1 reactor spent fuel basin for extended periods. In these field tests the coupons coated with HTC from a high temperature (HT) bath and subsequently modified with Ce were the most resistant to pitting corrosion. In laboratory tests also, HT- hydrotalcite + Ce coated specimens were the most corrosion resistant in 0.01 M NaCl. The role of cerium in increasing the corrosion resistance imparted by the different conversion coatings of spent Al-clad RR fuel elements is presented. (author)

  10. CO2 laser cladding heterogeneous ceramic-metal wear-resistant coatings

    Science.gov (United States)

    Fomin, V. M.; Malikov, A. G.; Orishich, A. M.

    2016-10-01

    The microstructure, hardness property and wear resistance of WC, Ni-Cr and Fe powders deposited by laser cladding at varying processing parameters were investigated. The results of the present study revealed the prospects of multilayer cladding of R6M5 high-speed tool steel (analog of M2 steel (USA) and HS6-5-2 steel (EU)) onto low-alloy steel with the use of a laser beam. Controlling thermal cycles of laser cladding, it is possible to obtain a clad coating made of high-speed steel having the structure of high-alloy austenite-martensite mixture with disperse inclusions of carbides up to 10 mm thick, i.e., it is actually possible to create bimetal structures. The wear resistance of the laser-clad self-fluxing PG-10N-01 (Ni-Cr-B-Si-C) alloy increases by a factor of 5 due to addi-tional hardening by cast tungsten carbide (WC) with spherical particles. As a result, it becomes higher than the wear resistance of high-speed steel by more than a factor of 3.

  11. U-Mo Foil/Cladding Interactions in Friction Stir Welded Monolithic RERTR Fuel Plates

    Energy Technology Data Exchange (ETDEWEB)

    D.D. Keiser; J.F. Jue; C.R. Clark

    2006-10-01

    Interaction between U-Mo fuel and Al has proven to dramatically impact the overall irradiation performance of RERTR dispersion fuels. It is of interest to better understand how similar interactions may affect the performance of monolithic fuel plates, where a uranium alloy fuel is sandwiched between aluminum alloy cladding. The monolithic fuel plate removes the fuel matrix entirely, which reduces the total surface area of the fuel that is available to react with the aluminum and moves the interface between the fuel and cladding to a colder region of the fuel plate. One of the major fabrication techniques for producing monolithic fuel plates is friction stir welding. This paper will discuss the interactions that can occur between the U-Mo foil and 6061 Al cladding when applying this fabrication technique. It has been determined that the time at high temperatures should be limited as much as is possible during fabrication or any post-fabrication treatment to reduce as much as possible the interactions between the foil and cladding. Without careful control of the fabrication process, significant interaction between the U-Mo foil and Al alloy cladding can result. The reaction layers produced from such interactions can exhibit notably different morphologies vis-à-vis those typically observed for dispersion fuels.

  12. Double Clad Er-doped Fiber Amplifier

    Institute of Scientific and Technical Information of China (English)

    FU Yong-jun; MAO Xiang-qiao; WEI Huai; LI jian

    2007-01-01

    Presented is a theoretical study of double-clad Er-doped fiber power amplifier(EDFA). Two kinds of double clad fibers(DCF) with rectangular and "flower" inner clad shapes are studied, and these fibers have different coupling constants and propagation losses. We calculate the effective pump power absorption ratio along the fiber with different coupling constants from the first cladding to the doped core and with different propagation losses for the power in the inner cladding. Then the gains of the double clad Er-doped fiber amplifiers versus fiber lengths are calculated using the EDFA model based on propagation and rate equations of a homogeneous, two-level medium.

  13. Kinetics of aluminum lithium alloys

    Science.gov (United States)

    Pletcher, Ben A.

    2009-12-01

    Aluminum lithium alloys are increasingly used in aerospace for their high strength-to-weight ratio. Additions of lithium, up to 4.2 wt% decrease the alloy density while increasing the modulus and yield strength. The metastable, second phase Al3Li or delta' is intriguing, as it remains spherical and coherent with the matrix phase, alpha, well into the overaged condition. Small interfacial strain energy allows these precipitates to remain spherical for volume fractions (VV ) of delta' less than 0.3, making this alloy system ideal for investigation of late-stage coarsening phenomena. Experimental characterization of three binary Al-Li alloys are presented as a critical test of diffusion screening theory and multi-particle diffusion simulations. Quantitative transmission electron microscopy is used to image the precipitates directly using the centered dark-field technique. Images are analyzed autonomously within a novel Matlab function that determines the center and size of each precipitate. Particle size distribution, particle growth kinetics, and maximum particle size are used to track the precipitate growth and correlate with the predictions of screening theory and multi-particle diffusion simulations. This project is the first extensive study of Al-Li alloys, in over 25 years, applying modern transmission electron microscopy and image analysis techniques. Previous studies sampled but a single alloy composition, and measured far fewer precipitates. This study investigates 3 alloys with volume fractions of the delta precipitates, VV =0.1-0.27, aged at 225C for 1 to 10 days. More than 1000 precipitates were sampled per aging time, creating more statistically significant data. Experimental results are used to test the predictions based on diffusion screening theory and multi-particle aging simulations. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)

  14. Russian aluminum-lithium alloys for advanced reusable spacecraft

    Science.gov (United States)

    Charette, Ray O.; Leonard, Bruce G.; Bozich, William F.; Deamer, David A.

    1998-01-01

    Cryotanks that are cost-affordable, robust, fuel-compatible, and lighter weight than current aluminum design are needed to support next-generation launch system performance and operability goals. The Boeing (McDonnell Douglas Aerospace-MDA) and NASA's Delta Clipper-Experimental Program (DC-XA) flight demonstrator test bed vehicle provided the opportunity for technology transfer of Russia's extensive experience base with weight-efficient, highly weldable aluminum-lithium (Al-Li) alloys for cryogenic tank usage. As part of NASA's overall reusable launch vehicle (RLV) program to help provide technology and operations data for use in advanced RLVs, MDA contracted with the Russian Academy of Sciences (RAS/IMASH) for design, test, and delivery of 1460 Al-Li alloy liquid oxygen (LO2) cryotanks: one for development, one for ground tests, and one for DC-XA flight tests. This paper describes the development of Al-Li 1460 alloy for reusable LO2 tanks, including alloy composition tailoring, mechanical properties database, forming, welding, chemical milling, dissimilar metal joining, corrosion protection, completed tanks proof, and qualification testing. Mechanical properties of the parent and welded materials exceeded expectations, particularly the fracture toughness, which promise excellent reuse potential. The LO2 cryotank was successfully demonstrated in DC-XA flight tests.

  15. Optimization of shearer sliding boots by plasma cladding with Cr4MnTi

    Institute of Scientific and Technical Information of China (English)

    Liu Hongtao; Wang Luping; Ge Shirong; Cao Shoufan; JinJing; Gao Jiping

    2011-01-01

    Severe production conditions in coal mines cause damage and failure problems with the oriented sliding boots of the mechanical shearer.Wear has been an especially vexing problem.Plasma cladding methods were used to study optimized sliding boot design.By cladding the substrate steel the surface may be made of a material more resistant to wear.The iron based alloy Cr4MnTi was coated onto a modified 45 steel matrix material in these tests.The results show that the alloy cladding layer is high strength,has high hardness,and is highly resistant to wear.After hardening and tempering,45 steel substrate has great tenacity so the combined structure meets the performance requirements for the construction of shearer sliding boots.

  16. Characterization of Fuel-Cladding Bond Strength Using Laser Shock

    Energy Technology Data Exchange (ETDEWEB)

    James A. Smith; David L. Cottle; Barry H. Rabin

    2014-04-01

    This paper describes new laser-based capabilities for characterization of fuel-cladding bond strength in nuclear fuels, and presents preliminary results obtained from studies on as-fabricated monolithic fuel consisting of uranium-10 wt.% molybdenum alloys clad in 6061 aluminum by hot isostatic pressing. Two complementary experimental methods are employed, laser-shock testing and laser-ultrasonic imaging. Measurements are spatially localized, non-contacting and require minimum specimen preparation, and are therefore ideally suited for applications involving radioactive materials, including irradiated materials. The theoretical principles and experimental approaches employed in characterization of nuclear fuel plates are described. The ability to measure layer thicknesses, elastic properties of the constituents, and the location and nature of laser-shock induced debonds is demonstrated, and preliminary bond strength measurement results are discussed.

  17. Removing hydrochloric acid exhaust products from high performance solid rocket propellant using aluminum-lithium alloy.

    Science.gov (United States)

    Terry, Brandon C; Sippel, Travis R; Pfeil, Mark A; Gunduz, I Emre; Son, Steven F

    2016-11-05

    Hydrochloric acid (HCl) pollution from perchlorate based propellants is well known for both launch site contamination, as well as the possible ozone layer depletion effects. Past efforts in developing environmentally cleaner solid propellants by scavenging the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., a salt instead of HCl). While this technique can potentially reduce HCl formation, it also results in reduced ideal specific impulse (ISP). Here, we show using thermochemical calculations that using aluminum-lithium (Al-Li) alloy can reduce HCl formation by more than 95% (with lithium contents ≥15 mass%) and increase the ideal ISP by ∼7s compared to neat aluminum (using 80/20 mass% Al-Li alloy). Two solid propellants were formulated using 80/20 Al-Li alloy or neat aluminum as fuel additives. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments (75.5±4.8% reduction in pH, ∝ [HCl], when compared to neat aluminum). Additionally, no measurable HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption.

  18. Friction surface cladding: An exploratory study of a new solid state cladding process

    NARCIS (Netherlands)

    Liu, S.J.; Bor, T.C.; Stelt, van der A.A.; Geijselaers, H.J.M.; Kwakernaak, C.; Kooijman, A.M.; Mol, J.M.C.; Akkerman, R.; Boogaard, van den A.H.

    2015-01-01

    Friction surface cladding is a newly developed solid state cladding process to manufacture thin metallic layers on a substrate. In this study the influence of process conditions on the clad layer appearance and the mechanical properties of both the clad layer and the substrate were investigated. Thi

  19. Five-Fold Branched Si Particles in Laser Clad AlSi Functionally Graded Materials

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2001-01-01

    Many five-fold branched Si particles (Sip) were observed in Al–40 wt% Si functionally graded materials produced by a single-step laser cladding process on cast Al-alloy substrate. In this paper the five-fold twinning and growth features of Sip are scrutinized with orientation imaging microscopy and

  20. Microstructure and abrasive wear studies of laser clad Al-Si/SiC composite coatings

    NARCIS (Netherlands)

    Anandkumar, R.; Colaco, R.; Ocelik, V.; De Hosson, J. Th. M.; Vilar, R.; Gyulai, J; Szabo, PJ

    2007-01-01

    Surface coatings of Al-Si/SiC metal-matrix composites were deposited on Al-7 wt. % Si alloy substrates by laser cladding. The microstructure of the coatings was characterized by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The microstructure of the coating mate

  1. Tribological behaviour of laser-clad TiCp composite coating

    NARCIS (Netherlands)

    Ouyang, J.H.; Pei, Y.T.; Lei, T.C.; Zhou, Y.

    1995-01-01

    The wear behaviour of laser-clad TiC-Ni alloy coatings was studied by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and pin-on-ring friction and wear tests. TiC particles can act as hard barriers to resist the scoring and plastic deformation of the matrix and then

  2. Fabrication and testing of U-7Mo monolithic plate fuel with Zircaloy cladding

    Science.gov (United States)

    Pasqualini, E. E.; Robinson, A. B.; Porter, D. L.; Wachs, D. M.; Finlay, M. R.

    2016-10-01

    Nuclear fuel designs are being developed to replace highly enriched fuel used in research and test reactors with fuels of low enrichment. In the most challenging cases, U-(7-10 wt%)Mo monolithic plate fuels are proposed. One of the considered designs includes aluminum-alloy cladding, which provides some challenges in fabrication and fuel/cladding interaction during service. Zircaloy cladding, specifically Zry-4, was investigated as an alternative cladding, and development of a fabrication method was performed by researchers with the Comisión Nacionalde Energia Atómica (CNEA) in Argentina, resulting in test fuel plates (Zry-4 clad U-7Mo) which were subsequently tested in the Advanced Test Reactor in Idaho. Because Zry-4 and U-(7-10)Mo have similar high-temperature mechanical properties, fabrication was simplified in that the fuel foil and cladding could be co-rolled and bonded. The challenge was to prevent a thermal-expansion mismatch, which could destroy the fuel/cladding bond before complete bonding was achieved; the solution was to prevent the composites from cooling significantly during or between roll passes. The final product performed very well in-reactor, showing good bonding, very little fuel/cladding interaction-either from fabrication or in-reactor testing-and little swelling, especially no detectable heterogeneous bubble formation at the fuel/cladding interface tested to a fission density of up to 2.7E+21 (average) fissions/cm3, 3.8E+21 (peak).

  3. Clad Degradation - FEPs Screening Arguments

    Energy Technology Data Exchange (ETDEWEB)

    E. Siegmann

    2004-03-17

    The purpose of this report is to document the screening of the cladding degradation features, events, and processes (FEPs) for commercial spent nuclear fuel (CSNF). This report also addresses the effect of some FEPs on both the cladding and the CSNF, DSNF, and HLW waste forms where it was considered appropriate to address the effects on both materials together. This report summarizes the work of others to screen clad degradation FEPs in a manner consistent with, and used in, the Total System Performance Assessment-License Application (TSPA-LA). This document was prepared according to ''Technical Work Plan for Waste Form Degradation Modeling, Testing, and Analyses in Support of LA'' (BSC 2004a [DIRS 167796]).

  4. Status Report on the Fabrication of Fuel Cladding Chemical Interaction Test Articles for ATR Irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, Richard H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-28

    FeCrAl alloys are a promising new class of alloys for light water reactor (LWR) applications due to their superior oxidation and corrosion resistance in high temperature environments. The current R&D efforts have focused on the alloy composition and processing routes to generate nuclear grade FeCrAl alloys with optimized properties for enhanced accident tolerance while maintaining properties needed for normal operation conditions. Therefore, the composition and processing routes must be optimized to maintain the high temperature steam oxidation (typically achieved by increasing the Cr and Al content) while still exhibiting properties conducive to normal operation in a LWR (such as radiation tolerance where reducing Cr content is favorable). Within this balancing act is the addition of understanding the influence on composition and processing routes on the FeCrAl alloys for fuel-cladding chemical interactions (FCCI). Currently, limited knowledge exists on FCCI for the FeCrAl-UO2 clad-fuel system. To overcome the knowledge gaps on the FCCI for the FeCrAl-UO2 clad-fuel system a series of fueled irradiation tests have been developed for irradiation in the Advanced Test Reactor (ATR) housed at the Idaho National Laboratory (INL). The first series of tests has already been reported. These tests used miniaturized 17x17 PWR fuel geometry rodlets of second-generation FeCrAl alloys fueled with industrial Westinghouse UO2 fuel. These rodlets were encapsulated within a stainless steel housing.To provide high fidelity experiments and more robust testing, a new series of rodlets have been developed deemed the Accident Tolerant Fuel Experiment #1 Oak Ridge National Laboratory FCCI test (ATF-1 ORNL FCCI). The main driving factor, which is discussed in detail, was to provide a radiation environment where prototypical fuel-clad interface temperatures are met while still maintaining constant contact between industrial fuel and the candidate cladding alloys

  5. Electrochemical behaviour of laser-clad Ti6Al4V with CP Ti in 0.1 M oxalic acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Obadele, Babatunde Abiodun, E-mail: obadele4@gmail.com [Institute for NanoEngineering Research, Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Olubambi, Peter A. [Institute for NanoEngineering Research, Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Andrews, Anthony [Institute for NanoEngineering Research, Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Department of Materials Engineering, Kwame Nkrumah University of Science and Technology, Kumasi (Ghana); Pityana, Sisa [Institute for NanoEngineering Research, Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); National Laser Center, Council for Scientific and Industrial Research, Pretoria (South Africa); Mathew, Mathew T. [Institute for NanoEngineering Research, Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL 60612 (United States)

    2015-10-15

    The relationship between the microstructure and corrosion behaviour of Ti6Al4V alloy and laser-clad commercially pure (CP) Ti coating was investigated. The microstructure, phases and properties of the clad layers were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Electrochemical measurement techniques including open circuit potential (OCP) and potentiodynamic polarisation were used to evaluate the corrosion behaviour of Ti6Al4V alloy in 0.1 M oxalic acid solution and the results compared to the behaviour of laser-clad CP Ti at varying laser scan speed. Results showed that laser-clad CP Ti at scan speed of 0.4 m/min formed a good cladding layer without defects such as cracks and pores. The phase present in the cladding layer was mostly α′-Ti. The microstructures of the clad layer were needle like acicular/widmanstätten α. An improvement in the microhardness values was also recorded. Although the corrosion potentials of the laser-clad samples were less noble than Ti6Al4V alloy, the polarisation measurement showed that the anodic current density was lower and also increases with increasing laser scanning speed. - Highlights: • The microstructure and corrosion behaviour of laser-clad CP Ti was investigated. • Laser-clad CP Ti 0.4 m/min scan speed gave a good coating without cracks and pores. • The phase present in the clad layer was mostly α′-Ti. • An improvement in the microhardness values was also recorded. • Anodic current density for coatings increases with increasing laser scan speed.

  6. Influence of Lanthanum on Tribological Properties and Microstructure of Laser Clad B+Fe+Si Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    程西云; 谢学兵; 蒋松

    2004-01-01

    The effects of rare earth ferrosilicon on the microstructure and anti-wear properties of laser-clad Fe-based alloy coating were investigated. The composition of Fe,B4C and rare earth ferrosilicon powders with different contents of lanthanum were clad onto a 45# carbon steel substrate. Microstructural features,chemical compositions,phase structure,hardness,friction and wear properties by scanning electron microscopy(SEM),X-ray photoelectron microscopy(XPS),hardness tester,block-on-ring friction and wear tester of the clad coating were determined. Experimental results show that the friction coefficient of the clad coating doped with rare earth ferrosilicon is reduced while the wear resistance of clad coating doped with rare earth ferrosilicon is enhanced. When the content of lanthanum increases to 1.92%,the clad coating shows the best anti-wear ability,and as the content of lanthanum exceeds 1.92%,the wear weight loss increases quickly. The rare earth ferrosilicon to be doped in the clad coatings helps to disperse the boride phase(Fe2B,FeB,B4C) particles and refine the grain of boride phase. The enhancement of clad coating's wear resistance is due to the existence of dispersed boride phases.

  7. WC颗粒对激光熔覆FeCoCrNiCu高熵合金涂层组织与硬度的影响%Effects of WC Particles on the Microstructure and Hardness of FeCoCrNiCu High-entropy Alloy Coating Prepared by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    黄祖凤; 张冲; 唐群华; 戴品强; 吴波

    2013-01-01

    FeCoCrNiCu high-entropy alloy coating with WC particles was prepared by the continuous wave CO2 laser. The effects of WC particles on the microstructure and hardness were investigated. Results show that the high entropy alloy coatings with different WC content are all composed of face-centered cubic (FCC) and body-centered cubic (BCC) solid solution phases. With the increase of WC content, BCC phase content increases and FCC phase content decreases. During the process of laser cladding, WC particles dissolved into the FCC and BCC phases, however, the addition of WC does not cause the formation of complex carbide phases. The microstructure of coatings with different WC content is typical dendrite. Element segregation between the dendrite and interdendrite can be effectively inhibited by laser cladding with rapid solidification. The increase of WC content lead to grain refinement and microhardness increasing.%采用CO2横流激光器制备添加WC颗粒的FeCoCrNiCu高熵合金涂层,研究WC含量对涂层的组织结构及硬度的影响.结果表明:不同WC含量的高熵合金涂层均由简单的面心立方结构(FCC)和体心立方结构(BCC)两相组成.随着WC含量的提高,涂层中FCC相含量不断减少,BCC相含量不断增加.WC颗粒在激光熔覆过程中发生溶解并完全溶入FCC相和BCC相中,并未引起复杂碳化物相的生成.不同WC含量的涂层均为树枝晶组织.激光熔覆过程中的快速凝固条件有利于抑制枝晶和枝晶间的成分偏聚.WC含量的提高使枝晶细化,硬度提高.

  8. Capture of Tritium Released from Cladding in the Zirconium Recycle Process

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Barry B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Walker, T. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, S. H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DelCul, Guillermo Daniel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-31

    Zirconium may be recovered from the Zircaloy® cladding of used nuclear fuel (UNF) for recycle or to reduce the quantities of high-level waste destined for a geologic repository. Recovery of zirconium using a chlorination process is currently under development at the Oak Ridge National Laboratory. The approach is to treat the cladding with chlorine gas to convert the zirconium in the alloy (~98 wt % of the alloy mass) to zirconium tetrachloride. A significant fraction of the tritium (0–96%) produced in nuclear fuel during irradiation may be found in zirconium-based cladding and could be released from the cladding when the solid matrix is destroyed by the chlorination reaction. To prevent uncontrolled release of radioactive tritium to other parts of the plant or to the environment, a method to recover the tritium may be required. The focus of this effort was to (1) identify potential methods for the recovery of tritium from the off-gas of the zirconium recycle process, (2) perform scoping tests on selected recovery methods using nonradioactive gas simulants, and (3) select a process design appropriate for testing on radioactive gas streams generated by the engineering-scale zirconium recycle demonstrations on radioactive used cladding.

  9. Capture of Tritium Released from Cladding in the Zirconium Recycle Process

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Barry B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Walker, T. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DelCul, Guillermo Daniel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-31

    This report is issued as the first revision to FCRD-MRWFD-2016-000297. Zirconium may be recovered from the Zircaloy® cladding of used nuclear fuel (UNF) for recycle or to reduce the quantities of high-level waste destined for a geologic repository. Recovery of zirconium using a chlorination process is currently under development at the Oak Ridge National Laboratory. The approach is to treat the cladding with chlorine gas to convert the zirconium in the alloy (~98 wt % of the alloy mass) to zirconium tetrachloride. A significant fraction of the tritium (0–96%) produced in nuclear fuel during irradiation may be found in zirconium-based cladding and could be released from the cladding when the solid matrix is destroyed by the chlorination reaction. To prevent uncontrolled release of radioactive tritium to other parts of the plant or to the environment, a method to recover the tritium may be required. The focus of this effort was to (1) identify potential methods for the recovery of tritium from the off-gas of the zirconium recycle process, (2) perform scoping tests on selected recovery methods using non-radioactive gas simulants, and (3) select a process design appropriate for testing on radioactive gas streams generated by the engineering-scale zirconium recycle demonstrations on radioactive used cladding.

  10. The influence of cladding on fission gas release from irradiated U-Mo monolithic fuel

    Science.gov (United States)

    Burkes, Douglas E.; Casella, Amanda J.; Casella, Andrew M.

    2017-04-01

    The monolithic uranium-molybdenum (U-Mo) alloy has been proposed as a fuel design capable of converting the world's highest power research reactors from use of high enriched uranium to low enriched uranium. However, a zirconium (Zr) diffusion barrier must be used to eliminate interactions that form between the U-Mo monolith and aluminum alloy 6061 (AA6061) cladding during fabrication and are enhanced during irradiation. One aspect of fuel development and qualification is to demonstrate an appropriate understanding of the extent of fission product release from the fuel under anticipated service environments. An exothermic reaction has previously been observed between the AA6061 cladding and Zr diffusion layer. In this paper, two fuel segments with different irradiation history were subjected to specified thermal profiles under a controlled atmosphere using a thermogravimetric/differential thermal analyzer coupled with a mass spectrometer inside a hot cell. Samples from each segment were tested with cladding and without cladding to investigate the effect, if any, that the exothermic reaction has on fission gas release mechanisms. Measurements revealed there is an instantaneous effect of the cladding/Zr exothermic reaction, but not necessarily a cumulative effect above approximately 973 K (700 °C). The mechanisms responsible for fission gas release events are discussed.

  11. Screening of advanced cladding materials and UN-U3Si5 fuel

    Science.gov (United States)

    Brown, Nicholas R.; Todosow, Michael; Cuadra, Arantxa

    2015-07-01

    In the aftermath of Fukushima, a focus of the DOE-NE Advanced Fuels Campaign has been the development of advanced nuclear fuel and cladding options with the potential for improved performance in an accident. Uranium dioxide (UO2) fuels with various advanced cladding materials were analyzed to provide a reference for cladding performance impacts. For advanced cladding options with UO2 fuel, most of the cladding materials have some reactivity and discharge burn-up penalty (in GWd/t). Silicon carbide is one exception in that the reactor physics performance is predicted to be very similar to zirconium alloy cladding. Most candidate claddings performed similar to UO2-Zr fuel-cladding in terms of safety coefficients. The clear exception is that Mo-based materials were identified as potentially challenging from a reactor physics perspective due to high resonance absorption. This paper also includes evaluation of UN-U3Si5 fuels with Kanthal AF or APMT cladding. The objective of the U3Si5 phase in the UN-U3Si5 fuel concept is to shield the nitride phase from water. It was shown that UN-U3Si5 fuels with Kanthal AF or APMT cladding have similar reactor physics and fuel management performance over a wide parameter space of phase fractions when compared to UO2-Zr fuel-cladding. There will be a marginal penalty in discharge burn-up (in GWd/t) and the sensitivity to 14N content in UN ceramic composites is high. Analysis of the rim effect due to self-shielding in the fuel shows that the UN-based ceramic fuels are not expected to have significantly different relative burn-up distributions at discharge relative to the UO2 reference fuel. However, the overall harder spectrum in the UN ceramic composite fuels increases transuranic build-up, which will increase long-term activity in a once-thru fuel cycle but is expected to be a significant advantage in a fuel cycle with continuous recycling of transuranic material. It is recognized that the fuel and cladding properties assumed in

  12. FY 2014 Status Report: of Vibration Testing of Clad Fuel (M4FT-14OR0805033)

    Energy Technology Data Exchange (ETDEWEB)

    Bevard, Bruce Balkcom [ORNL

    2014-03-28

    The DOE Used Fuel Disposition Campaign (UFDC) tasked Oak Ridge National Laboratory (ORNL) to investigate the behavior of light-water-reactor (LWR) fuel cladding material performance related to extended storage and transportation of UNF. ORNL has been tasked to perform a systematic study on UNF integrity under simulated normal conditions of transportation (NCT) by using the recently developed hot-cell testing equipment, Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT). To support the testing on actual high-burnup UNF, fast-neutron irradiation of pre-hydrided zirconium-alloy cladding in the High Flux Isotope Reactor (HFIR) at elevated temperatures will be used to simulate the effects of high-burnup on fuel cladding for help in understanding the cladding materials properties relevant to extended storage and subsequent transportation. The irradiated pre-hydrided metallic materials testing will generate baseline data to benchmark hot-cell testing of the actual high-burnup UNF cladding. More importantly, the HFIR-irradiated samples will be free of alpha contamination and can be provided to researchers who do not have hot cell facilities to handle highly contaminated high-burnup UNF cladding to support their research projects for the UFDC.

  13. Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hongbing [Univ. of Texas, Austin, TX (United States); Bukkapatnam, Satish; Harimkar, Sandip; Singh, Raman; Bardenhagen, Scott

    2014-01-09

    Enhancing performance of fuel cladding and duct alloys is a key means of increasing fuel burnup. This project will address the failure of fuel cladding via three-dimensional cracking models. Researchers will develop a simulation code for the failure of the fuel cladding and validate the code through experiments. The objective is to develop an algorithm to determine the failure of fuel cladding in the form of three-dimensional cracking due to prolonged exposure under varying conditions of pressure, temperature, chemical environment, and irradiation. This project encompasses the following tasks: 1. Simulate 3D crack initiation and growth under instantaneous and/or fatigue loads using a new variant of the material point method (MPM); 2. Simulate debonding of the materials in the crack path using cohesive elements, considering normal and shear traction separation laws; 3. Determine the crack propagation path, considering damage of the materials incorporated in the cohesive elements to allow the energy release rate to be minimized; 4. Simulate the three-dimensional fatigue crack growth as a function of loading histories; 5. Verify the simulation code by comparing results to theoretical and numerical studies available in the literature; 6. Conduct experiments to observe the crack path and surface profile in unused fuel cladding and validate against simulation results; and 7. Expand the adaptive mesh refinement infrastructure parallel processing environment to allow adaptive mesh refinement at the 3D crack fronts and adaptive mesh merging in the wake of cracks. Fuel cladding is made of materials such as stainless steels and ferritic steels with added alloying elements, which increase stability and durability under irradiation. As fuel cladding is subjected to water, chemicals, fission gas, pressure, high temperatures, and irradiation while in service, understanding performance is essential. In the fast fuel used in advanced burner reactors, simulations of the nuclear

  14. Advanced powder metallurgy aluminum alloys via rapid solidification technology, phase 2

    Science.gov (United States)

    Ray, Ranjan; Jha, Sunil C.

    1987-01-01

    Marko's rapid solidification technology was applied to processing high strength aluminum alloys. Four classes of alloys, namely, Al-Li based (class 1), 2124 type (class 2), high temperature Al-Fe-Mo (class 3), and PM X7091 type (class 4) alloy, were produced as melt-spun ribbons. The ribbons were pulverized, cold compacted, hot-degassed, and consolidated through single or double stage extrusion. The mechanical properties of all four classes of alloys were measured at room and elevated temperatures and their microstructures were investigated optically and through electron microscopy. The microstructure of class 1 Al-Li-Mg alloy was predominantly unrecrystallized due to Zr addition. Yield strengths to the order of 50 Ksi were obtained, but tensile elongation in most cases remained below 2 percent. The class 2 alloys were modified composition of 2124 aluminum alloy, through addition of 0.6 weight percent Zr and 1 weight percent Ni. Nickel addition gave rise to a fine dispersion of intermetallic particles resisting coarsening during elevated temperature exposure. The class 2 alloy showed good combination of tensile strength and ductility and retained high strength after 1000 hour exposure at 177 C. The class 3 Al-Fe-Mo alloy showed high strength and good ductility both at room and high temperatures. The yield and tensile strength of class 4 alloy exceeded those of the commercial 7075 aluminum alloy.

  15. Property of AlCrCoFeNiMoTi0.75 Si0.25 High-entropy Alloy Coating Tool Prepared by Laser Cladding%激光熔覆AlCrCoFeNiMoTi0.75Si0.25高熵合金涂层刀具的性能

    Institute of Scientific and Technical Information of China (English)

    张爱荣; 梁红玉; 李烨

    2013-01-01

    利用激光熔覆技术制备了AlCrCoFeNiMoTi0.75Si025高熵合金涂层刀具,研究了激光快速凝固和经过1 000℃退火处理的AlCrCoFeNiMoTi0.75Si0.25高熵合金涂层微观组织和硬度、摩擦磨损性能,并比较了普通高速钢及高熵合金涂层刀具的切削加工性能.结果表明:激光熔覆AlCrCoFeNiMoTi0.5Si0.5高熵合金涂层的主要相结构为bcc相,涂层具有较好的高温稳定性.激光熔覆高熵合金涂层刀具表面硬度高,摩擦因数小,断屑效果好,被加工材料表面光洁度高.%AlCrCoFeNiMoTi0.75Si0.25 high-entropy alloy coated cutting tools was prepared by laser cladding.The microstructure,hardness,friction and wear properties of the AlCrCoFeNiMoTi0.75Si0.25 high-entropy alloy coatings prepared by laser rapid solidification and annealing treatment at 1 000 ℃ were studied.The machinability of the high-speed-steel tools and high-entropy alloy coated tools was compared.Results show that the main alloy structure of the coating is a body centered cubic (BCC) and the coating performs high tempera ture stability.The high-entropy coated cutting tool is characterized by higher hardness,lower friction coefficient,better chip breaker,and better surface finish of the machined materials.

  16. 不锈钢铝合金半固态连接工艺参数研究%Technological parameters of stainless steel-aluminum alloy semisolid joining clad

    Institute of Scientific and Technical Information of China (English)

    刘洪伟; 郭成

    2007-01-01

    By using semisolid joining technique, the bonding of stainless steel and semisolid aluminum alloy is successfully realized. The relationships between interfacial shear strength and solid fraction of aluminum alloy, bonding pressure and time of keeping pressure were studied by the method of orthogonal experiment. The interfacial structure and the fracture structure of the bonding plate are studied by means of optical microscope (OM) and scanning electron microscope (SEM). The results show that there is the best solid fraction between the solid phase line and the liquid phase line of the semisolid aluminum alloy, with the increase of bonding pressure and pressure time, the interfacial shear strength increases rapidly, and then with further increase of bonding pressure and pressure time, the shear strength rises little. Along the interface, solid phase and liquid phase bond with stainless steel by turns because of the different diffusion ability. So, a new type of non-equilibrium diffusion interfacial structure is constructed at the interface of stainless steel and aluminum alloy, compound mechanism of plastic and brittle fracture interface was formed at the shear fracture interface.

  17. Analysis of Nickel Based Hardfacing Materials Manufactured by Laser Cladding for Sodium Fast Reactor

    Science.gov (United States)

    Aubry, P.; Blanc, C.; Demirci, I.; Dal, M.; Malot, T.; Maskrot, H.

    For improving the operational capacity, the maintenance and the decommissioning of the future French Sodium Fast Reactor ASTRID which is under study, it is asked to find or develop a cobalt free hardfacing alloy and the associated manufacturing process that will give satisfying wear performances. This article presents recent results obtained on some selected nickel-based hardfacing alloys manufactured by laser cladding, particularly on Tribaloy 700 alloy. A process parameter search is made and associated the microstructural analysis of the resulting clads. A particular attention is made on the solidification of the main precipitates (chromium carbides, boron carbides, Laves phases,…) that will mainly contribute to the wear properties of the material. Finally, the wear resistance of some samples is evaluated in simple wear conditions evidencing promising results on tribology behavior of Tribaloy 700.

  18. Computer Simulation of Ordering and Atom Clustering in Aging Binary AI-Li Alloy

    Institute of Scientific and Technical Information of China (English)

    LIXiao-ling; CHENZheng; WANGYong-xin; HUMing-juan

    2004-01-01

    Ordering and atom clustering in aging binary Al-Li alloy has been investigated by computer simulation through calculating the long range order (lro.) parameter and composition deviation order parameter from single-site occupation probabilities of Li atom. The results show that when the alloy lies in metastable region in the phase diagram ordering and atom clustering occur simultaneously. As the composition of the alloy increases ordering occurs earlier than atom clustering gradually. When the alloy lies in instable region atom clustering takes place after the congruent ordering completes. It has also been found that the incubation period of the phase transformation is shortened as the composition increases.

  19. Effects of Lower Drying-Storage Temperature on the Ductility of High-Burnup PWR Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Billone, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Burtseva, T. A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-08-30

    The purpose of this research effort is to determine the effects of canister and/or cask drying and storage on radial hydride precipitation in, and potential embrittlement of, high-burnup (HBU) pressurized water reactor (PWR) cladding alloys during cooling for a range of peak drying-storage temperatures (PCT) and hoop stresses. Extensive precipitation of radial hydrides could lower the failure hoop stresses and strains, relative to limits established for as-irradiated cladding from discharged fuel rods stored in pools, at temperatures below the ductile-to-brittle transition temperature (DBTT).

  20. Screening of advanced cladding materials and UN–U{sub 3}Si{sub 5} fuel

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Nicholas R., E-mail: nbrown@bnl.gov; Todosow, Michael; Cuadra, Arantxa

    2015-07-15

    Highlights: • Screening methodology for advanced fuel and cladding. • Cladding candidates, except for silicon carbide, exhibit reactivity penalty versus zirconium alloy. • UN–U{sub 3}Si{sub 5} fuels have the potential to exhibit reactor physics and fuel management performance similar to UO{sub 2}. • Harder spectrum in the UN ceramic composite fuel increases transuranic build-up. • Fuel and cladding properties assumed in these assessments are preliminary. - Abstract: In the aftermath of Fukushima, a focus of the DOE-NE Advanced Fuels Campaign has been the development of advanced nuclear fuel and cladding options with the potential for improved performance in an accident. Uranium dioxide (UO{sub 2}) fuels with various advanced cladding materials were analyzed to provide a reference for cladding performance impacts. For advanced cladding options with UO{sub 2} fuel, most of the cladding materials have some reactivity and discharge burn-up penalty (in GWd/t). Silicon carbide is one exception in that the reactor physics performance is predicted to be very similar to zirconium alloy cladding. Most candidate claddings performed similar to UO{sub 2}–Zr fuel–cladding in terms of safety coefficients. The clear exception is that Mo-based materials were identified as potentially challenging from a reactor physics perspective due to high resonance absorption. This paper also includes evaluation of UN–U{sub 3}Si{sub 5} fuels with Kanthal AF or APMT cladding. The objective of the U{sub 3}Si{sub 5} phase in the UN–U{sub 3}Si{sub 5} fuel concept is to shield the nitride phase from water. It was shown that UN–U{sub 3}Si{sub 5} fuels with Kanthal AF or APMT cladding have similar reactor physics and fuel management performance over a wide parameter space of phase fractions when compared to UO{sub 2}–Zr fuel–cladding. There will be a marginal penalty in discharge burn-up (in GWd/t) and the sensitivity to {sup 14}N content in UN ceramic composites is high

  1. Bioactivity of calcium phosphate bioceramic coating fabricated by laser cladding

    Science.gov (United States)

    Zhu, Yizhi; Liu, Qibin; Xu, Peng; Li, Long; Jiang, Haibing; Bai, Yang

    2016-05-01

    There were always strong expectations for suitable biomaterials used for bone regeneration. In this study, to improve the biocompatiblity of titanium alloy, calcium phosphate bioceramic coating was obtained by laser cladding technology. The microstructure, phases, bioactivity, cell differentiation, morphology and resorption lacunae were investigated by optical microscope (OM), x-ray diffraction (XRD), methyl thiazolyl tetrazolium (MTT) assay, tartrate-resistant acid phosphatase (TRAP) staining and scanning electronic microscope (SEM), respectively. The results show that bioceramic coating consists of three layers, which are a substrate, an alloyed layer and a ceramic layer. Bioactive phases of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) were found in ceramic coating. Osteoclast precursors have excellent proliferation on the bioceramic surface. The bioceramics coating could be digested by osteoclasts, which led to the resorption lacunae formed on its surface. It revealed that the gradient bioceramic coating has an excellent bioactivity.

  2. Weld overlay cladding with iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, G.M. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    The author has established a range of compositions for these alloys within which hot cracking resistance is very good, and within which cold cracking can be avoided in many instances by careful control of welding conditions, particularly preheat and postweld heat treatment. For example, crack-free butt welds have been produced for the first time in 12-mm thick wrought Fe{sub 3}Al plate. Cold cracking, however, still remains an issue in many cases. The author has developed a commercial source for composite weld filler metals spanning a wide range of achievable aluminum levels, and are pursuing the application of these filler metals in a variety of industrial environments. Welding techniques have been developed for both the gas tungsten arc and gas metal arc processes, and preliminary work has been done to utilize the wire arc process for coating of boiler tubes. Clad specimens have been prepared for environmental testing in-house, and a number of components have been modified and placed in service in operating kraft recovery boilers. In collaboration with a commercial producer of spiral weld overlay tubing, the author is attempting to utilize the new filler metals for this novel application.

  3. CLAD DEGRADATION - FEPS SCREENING ARGUMENTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Schreiner

    2004-10-21

    The purpose of this report is to evaluate and document the screening of the clad degradation features, events, and processes (FEPs) with respect to modeling used to support the Total System Performance Assessment-License Application (TSPA-LA). This report also addresses the effect of certain FEPs on both the cladding and the commercial spent nuclear fuel (CSNF), DOE-owned spent nuclear fuel (DSNF), and defense high-level waste (DHLW) waste forms, as appropriate to address the effects on multiple materials and both components (FEPs 2.1.09.09.0A, 2.1.09.11.0A, 2.1.11.05.0A, 2.1.12.02.0A, and 2.1.12.03.0A). These FEPs are expected to affect the repository performance during the postclosure regulatory period of 10,000 years after permanent closure. Table 1-1 provides the list of cladding FEPs, including their screening decisions (include or exclude). The primary purpose of this report is to identify and document the analysis, screening decision, and TSPA-LA disposition (for included FEPs) or screening argument (for excluded FEPs) for these FEPs related to clad degradation. In some cases, where a FEP covers multiple technical areas and is shared with other FEP reports, this report may provide only a partial technical basis for the screening of the FEP. The full technical basis for shared FEPs is addressed collectively by the sharing FEP reports. The screening decisions and associated TSPA-LA dispositions or screening arguments from all of the FEP reports are cataloged in a project-specific FEPs database.

  4. Wear behavior and corrosion resistance of NiCrAl/TiC composite coating on aluminum alloy by laser cladding%铝合金表面激光熔覆NiCrAl/TiC复合涂层的磨损行为和耐蚀性能

    Institute of Scientific and Technical Information of China (English)

    李琦; 刘洪喜; 张晓伟; 姚爽; 张旭

    2014-01-01

    为提高铝合金的摩擦磨损和耐蚀性能,在A390铝合金基体上通过激光熔覆制备NiCrAl/TiC复合涂层。采用XRD和EDS分析了涂层的物相组成,结合SEM观察了涂层的微观组织,运用摩擦磨损试验机和电化学工作站测试了涂层的摩擦磨损和耐腐蚀性能。结果表明:复合涂层主要物相为AlNi、Al 3 Ni 2、TiC ,同时含有少量的Cr 13 Ni 5 Si 2、Cu 9 Al 4和α(Al)。涂层自下至上分别为短棒状树枝晶、胞状晶、柱状树枝晶和等轴晶。相同磨损条件下,A390基体发生了严重的磨粒磨损和剥层磨损,而激光熔覆涂层只产生了轻微的磨粒磨损,熔覆层的相对耐磨性为3.16。在3.5%NaCl溶液中的极化曲线和电化学阻抗谱(EIS)显示:熔覆层自腐蚀电位较A390基体的正移,腐蚀电流密度减小;熔覆层呈单容抗特性,而A390基体在高频区表现为容抗特性,在中低频区则为感抗特性。在Bote图中,低频区熔覆层对应的相位角和中低频段熔覆层的阻抗模值均大于A390基体的,表明熔覆层的耐蚀性远高于A390基体的。熔覆层的腐蚀形貌为局部点蚀,A390基体的腐蚀形貌为晶间腐蚀和剥蚀。%In order to improve the frictional wear behavior and corrosion resistance of aluminum alloy, NiCrAl/TiC composite coating was fabricated on A390 aluminum alloy by laser cladding. The phase constitution, microstructure, frictional wear behavior and corrosion resistance of the composite coating were analyzed using X-ray diffraction (XRD), energy dispersive spectrum (EDS), scanning electron microscope (SEM), friction and wear testing machine and electrochemical workstation. The results show that the coating is mainly composed of AlNi, Al 3 Ni 2 and TiC phases, and a small amount of Cr13Ni5Si2, Cu9Al4 and α(Al) phases. The microstructures of the coating from the bottom to top are dendrite crystal, cellular crystal, columnar dendrite crystal and equiaxed

  5. 钛合金激光熔覆硬质颗粒增强金属间化合物复合涂层耐磨性%Wear Resistance of Laser Clad Hard Particles Reinforced Intermetallic Composite Coating on TA15 Alloy

    Institute of Scientific and Technical Information of China (English)

    冯淑容; 张述泉; 王华明

    2012-01-01

    A wear resistant hard particles reinforced intermetallic composite coating is fabricated on TA15 titanium alloy by the laser cladding process using 54. 51Ti-37. 68Ni-7. 81B4C powder blends as the precursor materials. Microstructure and worn surface morphologies of the coating are characterized by optical microscopy (OM), scan electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Wear resistance of the coating is evaluated under abrasive wear condition. Results indicate the hard particles including additional B,C and in situ synthesized titanium boride and titanium carbide are uniformly distributed in the TiNi/Ti2Ni dual-phase intermetallic matrix. The coating has high hardness and exhibits excellent wear resistance. The mainly wear mechanism of laser clad coating is slight micro-cutting and plastic deformation.%以54.51Ti-37.68Ni-7.81B4C(元素前数字为质量分数值)粉末混合物为原料,利用激光熔覆技术在TA15钛合金基材表面制得了以外加未熔B4C颗粒及快速凝固“原位”生成硼化钛和碳化钛为增强相,以金属间化合物TiNi、Ti2Ni为基体的复合涂层.采用光学显微镜(OM)、X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)等手段分析了涂层显微组织,并测试了涂层的二体磨粒磨损性能.结果表明,激光熔覆硬质颗粒增强金属间化合物复合涂层硬度高、组织均匀并表现出优异的抗磨粒磨损性能.高硬度、高耐磨的B4C、硼化钛和碳化钛陶瓷增强相与高韧性TiNi/Ti2Ni金属间化合物基体的强韧结合是激光熔覆涂层优异耐磨性的主要原因,其磨损机理为轻微的显微切削和塑性变形.

  6. Experimental investigations of the laser cladding of protective coatings on preheated base material

    Science.gov (United States)

    Jendrzejewski, Rafal; Sliwinski, Gerard; Conde, Ana; Navas, Carmen; de Damborenea, Juan J.

    2004-06-01

    The laser cladding technique was applied to obtain Co-based stellite SF6 coatings on the chromium steel base. The coatings were prepared by means of a direct cladding of metal powder using a 1.2 kW cw CO2 laser stand with a controlled preheating of the substrate material. Results of the metallographic tests revealed a fine-grained, dendritic microstructure and proper metallic bonding between substrate and coating. A nearly constant concentration of mian elements at different areas of the coating cross-section indicated on homogeneous chemical composition of the laser-cladded SF6 alloy samples. A significant decrease of the micro-crack number with increasing temperature of the base preheating was observed. This was accompanied by a drop of the wear and corrosion resistance.

  7. Characterization of Brazed Joints of C-C Composite to Cu-clad-Molybdenum

    Science.gov (United States)

    Singh, M.; Asthana, R.

    2008-01-01

    Carbon-carbon composites with either pitch+CVI matrix or resin-derived matrix were joined to copper-clad molybdenum using two active braze alloys, Cusil-ABA (1.75% Ti) and Ticusil (4.5% Ti). The brazed joints revealed good interfacial bonding, preferential precipitation of Ti at the composite/braze interface, and a tendency toward de-lamination in resin-derived C-C composite due to its low inter-laminar shear strength. Extensive braze penetration of the inter-fiber channels in the pitch+CVI C-C composites was observed. The relatively low brazing temperatures (Cu-clad-Mo/braze interface and higher hardness in Ticusil (approx.85-250 HK) than in Cusil-ABA (approx.50-150 HK). These C-C/Cu-clad-Mo joints with relatively low thermal resistance may be promising for thermal management applications.

  8. Duplex stainless steel surface bay laser cladding; Modificacion de las propiedades superficiales de aceros inoxidables Duplex mediante recubrimientos por laser

    Energy Technology Data Exchange (ETDEWEB)

    Amigo, V.; Pineda, Y.; Segovia, F.; Vicente, A.

    2004-07-01

    Laser cladding is one of the most promising techniques to restore damaged surfaces and achieve properties similar to those of the base metal. In this work, duplex stainless steels have been cladded by a nickel alloy under different processing conditions. The influence of the beam speed and defocusing variables ha been evaluated in the microstructure both of the cladding and heat affected zone, HAZ. These results have been correlated to mechanical properties by means of microhardness measurements from cladding area to base metal through the interface. This technique has shown to be very appropriate to obtain controlled mechanical properties as they are determined by the solidification microstructure, originated by the transfer of mass and heat in the system. (Author) 21 refs.

  9. Modelling cladding response to changing conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tulkki, Ville; Ikonen, Timo [VTT Technical Research Centre of Finland ltd (Finland)

    2016-11-15

    The cladding of the nuclear fuel is subjected to varying conditions during fuel reactor life. Load drops and reversals can be modelled by taking cladding viscoelastic behaviour into account. Viscoelastic contribution to the deformation of metals is usually considered small enough to be ignored, and in many applications it merely contributes to the primary part of the creep curve. With nuclear fuel cladding the high temperature and irradiation as well as the need to analyse the variable load all emphasise the need to also inspect the viscoelasticity of the cladding.

  10. Advanced Fuels Campaign Cladding & Coatings Meeting Summary

    Energy Technology Data Exchange (ETDEWEB)

    Not Listed

    2013-03-01

    The Fuel Cycle Research and Development (FCRD) Advanced Fuels Campaign (AFC) organized a Cladding and Coatings operational meeting February 12-13, 2013, at Oak Ridge National Laboratory (ORNL). Representatives from the U.S. Department of Energy (DOE), national laboratories, industry, and universities attended the two-day meeting. The purpose of the meeting was to discuss advanced cladding and cladding coating research and development (R&D); review experimental testing capabilities for assessing accident tolerant fuels; and review industry/university plans and experience in light water reactor (LWR) cladding and coating R&D.

  11. Plasmonic waveguides with hyperbolic multilayer cladding

    CERN Document Server

    Babicheva, Viktoriia E; Ishii, Satoshi; Boltasseva, Alexandra; Kildishev, Alexander V

    2014-01-01

    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence, are strongly absorbed. By avoiding the resonant widths in the design of the actual waveguides, the strong absorption can be eliminated.

  12. Optimization of Ni-Based WC/Co/Cr Composite Coatings Produced by Multilayer Laser Cladding

    Directory of Open Access Journals (Sweden)

    Andrea Angelastro

    2013-01-01

    Full Text Available As a surface coating technique, laser cladding (LC has been developed for improving wear, corrosion, and fatigue properties of mechanical components. The main advantage of this process is the capability of introducing hard particles such as SiC, TiC, and WC as reinforcements in the metallic matrix such as Ni-based alloy, Co-based alloy, and Fe-based alloy to form ceramic-metal composite coatings, which have very high hardness and good wear resistance. In this paper, Ni-based alloy (Colmonoy 227-F and Tungsten Carbides/Cobalt/Chromium (WC/Co/Cr composite coatings were fabricated by the multilayer laser cladding technique (MLC. An optimization procedure was implemented to obtain the combination of process parameters that minimizes the porosity and produces good adhesion to a stainless steel substrate. The optimization procedure was worked out with a mathematical model that was supported by an experimental analysis, which studied the shape of the clad track generated by melting coaxially fed powders with a laser. Microstructural and microhardness analysis completed the set of test performed on the coatings.

  13. Study on Laser Cladding NiAl/Al2O3 Coating on Magnesium Alloy%镁合金表面等离子喷涂NiAl/Al2O3涂层及激光重熔研究

    Institute of Scientific and Technical Information of China (English)

    钱建刚; 张家祥; 李淑青; 王纯

    2013-01-01

    A NiAl/Al2O3 coating was prepared on an AZ91D Mg alloy substrate by laser cladding of the plasma-sprayed coating.X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify the phases and to study the morphology,respectively.The adhesion strength and the porosity ratio of the coating material were measured by a tensile testing machine and an optical microscope (OM),respectively.The microhardness was measured using a micro Vickers hardness tester.The results show that after laser cladding metallurgical bonding occurrs at the interface between the NiAl transition layer and the substrate.The adhesion strength of the coating increases from 11.34 to 33.2 MPa.The coating became denser and the porosity ratio decrease from 10.23 % to 4.10 %.The metastable γ-Al2O3 phase in the coating without laser cladding is transformed completely into the stable α-Al2O3 phase.The microhardness HV0.05 is improved from 3290 to 5200 MPa,which is beneficial to the wear resistance.%利用等离子喷涂技术,在AZ91D镁合金表面制备NiAl/Al2O3涂层,并通过激光对涂层进行重熔处理.利用X射线衍射(XRD)和扫描电镜(SEM)测试手段分别研究了涂层在激光重熔前后的相组成和形貌,涂层的结合强度和孔隙率分别采用拉伸法和光学显微镜(OM)测量,利用显微硬度计测量重熔前后涂层的显微硬度.结果表明:经激光重熔处理后,NiAl过渡层与基体及Al2O3涂层界面处出现了具有冶金结合的特征,涂层的结合强度由原来的11.34提高到33.2 MPa;涂层的孔隙率则由原来的10.23%下降到4.10%,涂层变得更致密;涂层中的亚稳相γ-Al2O3全部转变为稳定相α-Al2O3;涂层的显微硬度HV0.05由3290MPa提高到5200MPa,有利于其耐磨性的提高.

  14. Rigorous modeling of cladding modes in photonic crystal fibers

    DEFF Research Database (Denmark)

    Rindorf, Lars Henning; Bang, Ole

    We study the cladding modes of a photonic crystal fiber (PCF) with a finite size cladding using a finite element method. The cladding consists of seven rings of air holes with bulk silica outside.......We study the cladding modes of a photonic crystal fiber (PCF) with a finite size cladding using a finite element method. The cladding consists of seven rings of air holes with bulk silica outside....

  15. The Toughening Technology of the Rapid Solidification Al - Li Alloys%快速冷凝(RS)Al-Li合金的韧化途径

    Institute of Scientific and Technical Information of China (English)

    石其年

    2003-01-01

    通过对快速冷凝(RS)Al-Li合金低塑韧性原因的分析,介绍了Al-Li合金制备、成材、热处理等过程中一些主要韧化途径,并简单讨论了获得较好综合性能的Al-Li合金制品的工艺方法及大致工艺参数范围.

  16. Modeling and simulation of hydrogen behavior in Zircaloy-4 fuel cladding

    Science.gov (United States)

    Courty, Olivier; Motta, Arthur T.; Hales, Jason D.

    2014-09-01

    As a result of corrosion during normal operation in nuclear reactors, hydrogen can enter the zirconium-alloy fuel cladding and precipitate as brittle hydride platelets, which can severely degrade the cladding ductility. Under a heterogeneous temperature distribution, hydrides tend to accumulate in the colder areas, creating local spots of degraded cladding that can favor crack initiation. Therefore, an estimation of the local hydride distribution is necessary to help predict the risk of cladding failure. The hydride distribution is governed by three competing phenomena. Hydrogen in solid solution diffuses under a concentration gradient due to Fick's law and under a temperature gradient due to the Soret effect. Precipitation of the hydride platelets occurs once the hydrogen solubility limit is reached. A model of these phenomena was implemented in the 3D fuel performance code BISON in order to calculate the hydrogen distribution for arbitrary geometries, such as a nuclear fuel rod, and is now available for BISON users. Simulations have been performed on simple geometries to validate the model and its implementation. The simulations predict that before precipitation occurs, hydrogen tends to accumulate in the colder spots due to the Soret effect. Once the solubility limit is reached, hydrogen precipitates and forms a rim close to the outer edge of the cladding. The simulations also predict that the reactor shut down has little effect on already precipitated hydrides but causes the remaining hydrogen to precipitate homogeneously into hydrides.

  17. Abrasive Performance of Chromium Carbide Reinforced Ni3Al Matrix Composite Cladding

    Institute of Scientific and Technical Information of China (English)

    LI Shang-ping; LUO He-li; FENG Di; CAO Xu; ZHANG Xi-e

    2009-01-01

    The Microstructure and room temperature abrasive wear resistance of chromium carbide reinforced NiM3Al matrix composite cladding at different depth on nickel base alloy were investigated. The results showed that there is a great difference in microstructure and wear resistance of the Ni3 Al matrix composite at different depth. Three kinds of tests, designed for different load and abrasive size, were used to understand the wear behaviour of this material. Under all three wear conditions, the abrasion resistance of the composite cladding at the depth of 6 mm, namely NC-M2, was much higher than that of the composite cladding at the depth of 2 mm, namely NC-M1. In addition, the wear-resistant advantage of NC-M2 was more obvious when the size of the abrasive was small. The relative wear resistance of NC-M2 increased from 1.63 times to 2.05 times when the size of the abrasive decreased from 180 μm to 50μm. The mierostructure of the composite cladding showed that the size of chromium carbide particles, which was mainly influenced by cooling rate of melting pool, was a function of distance from the interface between the coating and substrate varied gradually. The chromium carbide particles near the interface were finer than that far from inter-face, which was the main reason for the different wear resistance of the composite cladding at different depth.

  18. Galvanic corrosion of Mg-Zr fuel cladding and steel immobilized in Portland cement and geopolymer at early ages

    Science.gov (United States)

    Rooses, Adrien; Lambertin, David; Chartier, David; Frizon, Fabien

    2013-04-01

    Galvanic corrosion behaviour of Mg-Zr alloy fuel cladding and steel has been studied in Ordinary Portland cement and Na-geopolymer. Portland cements implied the worse magnesium corrosion performances due to the negative effects of cement hydrates, grinding agents and gypsum on the galvanic corrosion. Galvanic corrosion in Na-geopolymer paste remains very low. Silicates and fluoride from the geopolymer activation solution significantly improve the corrosion resistance of the magnesium alloy while coupling with a cathode.

  19. Micromechanical models of delamination in aluminum-lithium alloys

    Science.gov (United States)

    Messner, Mark Christian

    Aluminum lithium (Al-Li) alloys are lighter, stiffer, and tougher than conventional aerospace aluminum alloys. Replacing conventional aluminums with Al-Li could substantially decrease the weight and cost of aerospace structures. However, Al-Li alloys often fracture intergranularly via a mechanism called delamination cracking. While secondary delamination cracks can improve the effective toughness of a component, no current model accurately predicts the initiation and growth of intergranular cracks. Since simulations cannot incorporate delamination into a structural model, designers cannot quantify the effect of delamination cracking on a particular component. This uncertainty limits the application of Al-Li alloys. Previous experiments identify microstructural features linked to delamination. Fractography of failed surfaces indicates plastic void growth triggers intergranular failure. Furthermore, certain types of soft/stiff grain boundaries tend to localize void growth and nucleate delamination cracks. This dissertation develops a mechanism for the initiation of delamination on the microscale that accounts for these experimental observations. Microscale simulations of grain boundaries near a long primary crack explore the delamination mechanism on the mesoscale. In these simulations, a physically-based crystal plasticity (CP) model represents the constitutive response of individual grains. This CP model incorporates plastic voriticity correction terms into a standard objective stress rate integration, to accurately account for the kinematics of lattice deformation. The CP model implements slip system hardening with a modular approach to facilitate quick testing and calibration of different theories of hardening. The microscale models reveal soft/stiff grain boundaries develop elevated mean stress and plastic strain as a consequence of the mechanics of the interface. These elevated stresses and strain drive plastic void growth. The results indicate plastic void

  20. Inversion Solidification Cladding of H90-Steel

    Institute of Scientific and Technical Information of China (English)

    LI Bao-mian; XU Guang-ming; CUI Jian-zhong

    2008-01-01

    The variation law of cladding thickness as well as the structures and properties of H90-steel clad strip produced by inversion solidification was studied.The interface bonding mechanisms were approached.It is found that the thickness of H90 cladding goes sequentially through the solidification growth stage,holding stage,and remelting stage,with an increase in immersion time.The higher the preheating temperature of the steel coil,the thicker is the maximum cladding thickness.Observation by using optical microscopy (OM) and the electron probe microanalyzer (EPMA) shows that the microstrueture of H90 cladding is composed of equiaxed grains,and that interdiffusion between Cu and Fe at interface occurs but obvious diffusion of Zn and the intermetallic layer are not observed.The diffusion layer is thin and about 4 μm.Multipass small reduction cold rolling and repeated bending tests show that the interface is firmly bonded.Tensile test shows that the mechanical properties of the as-clad strips can meet the requirements of GB5213-2001 for the F-grade deep-drawing steel plate though there is a slight difference in the mechanical properties among the clad strips with different cladding thickness.

  1. Conference Proceedings of the Meeting of the Structures and Materials Panel of AGARD (67th) on New Light Alloys, Held in Mierlo, Netherlands on 3-5 October 1988

    Science.gov (United States)

    1989-08-01

    the sac • heat-treated condition. It was also found that Al-LI alloys exhibit excellent ductility and strength at liquid nitrogen temperature. The...pressage A ciatid des plaques ou des formes minces. Saul dans le cas o6 Ie pressage seffectue en phase semi -liqwide, le comportement plastique de Ia

  2. Reverse Transformation of Deformation-Induced Phases and Associated Changes in the Microstructure of Explosively Clad Ti-5Ta-2Nb and 304L SS

    Science.gov (United States)

    Prasanthi, T. N.; Sudha, C.; Murugesan, S.; Thomas Paul, V.; Saroja, S.

    2015-10-01

    Ti-5Ta-2Nb alloy was joined to 304L austenitic stainless steel by explosive cladding technique. Explosive cladding resulted in the formation of deformation-induced martensite in 304L SS and fcc phase of Ti in the Ti-5Ta-2Nb side of the joint. The stability of these metastable phases was systematically studied using high-temperature X-ray diffraction technique and transmission electron microscopy, which enabled the optimization of the temperature window for post-cladding heat treatments.

  3. Flat-Cladding Fiber Bragg Grating Sensors for Large Strain Amplitude Fatigue Tests

    Directory of Open Access Journals (Sweden)

    Xijia Gu

    2010-08-01

    Full Text Available We have successfully developed a flat-cladding fiber Bragg grating sensor for large cyclic strain amplitude tests of up to ±8,000 με. The increased contact area between the flat-cladding fiber and substrate, together with the application of a new bonding process, has significantly increased the bonding strength. In the push-pull fatigue tests of an aluminum alloy, the plastic strain amplitudes measured by three optical fiber sensors differ only by 0.43% at a cyclic strain amplitude of ±7,000 με and 1.9% at a cyclic strain amplitude of ±8,000 με. We also applied the sensor on an extruded magnesium alloy for evaluating the peculiar asymmetric hysteresis loops. The results obtained were in good agreement with those measured from the extensometer, a further validation of the sensor.

  4. Effect of Electric Field on Conductivity and Vickers Hardness of an A1-Li Alloy

    Institute of Scientific and Technical Information of China (English)

    刘兵; 陈大融; 陈铮; 王永欣; 李晓玲

    2003-01-01

    Static electric fields were applied on an aluminium-lithium alloy during solution treatment.The conductivity and Vickers hardness of the quenched Al-Li alloy is changed with the effect of electric field.The Vickers hardness increases with the applied electric field for a certain solutionizing time but decreases with the time under an electric field.In the absence of the electric field,the Vickers hardness and the conductivity increase synchronously,while reversed after electric field treatment.Positive and negative electric fields had the similar effect.The change of the local electron density in alloy caused by electric field is presented to explain the effect.

  5. 激光熔覆原位生成NbC/Ni45合金涂层组织与性能的研究%Investigation of Microstructure and Poperties of NbC/Ni45 Alloy Composite Coating by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    谢颂京; 董刚

    2012-01-01

    The in situ synthesized NbC particles reinforced Ni-based alloy composite coating has been successfully prepared on 1045 steel substrate by laser cladding. The coating is free of pores and cracks with excellent bonding between the coating and the substrate. The microstructure of the coating is mainly composed of γ-Ni dendrite, a large amount of interdendritic eutectics, M23 (CB)6 type carbides and dispersed NbC particles. The growth mechanism of the NbC particles with cores is nucleation-growth and the un-melted niobium may act as the nucleation core for NbC. Compared to the pure Ni-based alloy coating, the hardness of the composite coating is increased about 36 %, giving a high average hardness of approximate HV0.2750. This is attributed to the presence of in situ synthesized NbC particles and their well distribution in the coating.%利用C02激光器在45#钢基体上成功制备了原位生成NbC颗粒增强的镍基合金涂层,涂层与基体呈现良好的冶金结合,无裂纹气孔等缺陷.涂层组织主要有γ-Ni树枝晶,枝晶间大量的共晶组织,M23 (CB)6型碳化物和弥散分布的原位生成的NbC颗粒组成.带核的NbC颗粒是以为完全溶解的Nb为核心在其上长大的.由于原位生成NbC颗粒在复合涂层中的均匀分布,使涂层的平均显微硬度高达HV0.2750,比纯Ni45合金涂层提高了约36%.

  6. КВАЗИБИНАРНЫЕ РАЗРЕЗЫ И ПРОЕКЦИЯ ЛИКВИДУСА СИСТЕМЫ AL-LI-AL2CE

    OpenAIRE

    2006-01-01

    We have created ligvidus surface projection and equilibrium diagram of the system Al-Li-Al2Се using the method of different and thermal analysis of some polythermal sections of Al-Li-Al2Се.

  7. Crack Free Tungsten Carbide Reinforced Ni(Cr) Layers obtained by Laser Cladding

    OpenAIRE

    Amado Paz, José Manuel; Tobar Vidal, María José; YAÑEZ CASAL, ARMANDO JOSE; Amigó Borrás, Vicente; Candel Bou, Juan Jose

    2011-01-01

    The development of hardfacing coatings has become technologically significant in many industries A common approach is the production of metal matrix composites (MMC) layers. In this work NiCr-WC MMC hardfacing layers are deposited on C25 steel by means of laser cladding. Spheroidal fused tungsten carbides is used as reinforcement phase. Three different NiCr alloys with different Cr content were tested. Optimum conditions to obtain dense, uniform carbide distribution and hardness close to nomi...

  8. Solidification and microstructural aspects of laser-deposited Ni–Mo–Cr–Si alloy on stainless steel

    Indian Academy of Sciences (India)

    Reena Awasthi; Santosh Kumar; D Srivastava; G K Dey

    2010-12-01

    Laser cladding of stainless steel substrate was carried out using Ni–32Mo–15Cr–3Si (wt%) alloy powder. Laser cladding parameters were optimized to obtain defect-free and metallurgically bonded clad. Variation in solidification rate, cooling rate and compositional variation resulted in heterogeneous microstructure. Microstructure was found to be distinctly different in regions of clad cross-section. Majority of the region was found to consist of eutectic of Mo-rich hcp intermetallic Laves phase and NiFe fcc gamma solid solution phases. Extensive microstructural examinations of different clad regions have been carried out using microscopy and microanalysis techniques.

  9. Characterization of High Cycle Fatigue Behavior of a New Generation Aluminum Lithium Alloy (Preprint)

    Science.gov (United States)

    2011-07-01

    occurred along the boundary of two fracture surface facets indicating a typical intergranular type of failure. Although such extended de- lamination ... laminated region between the regularly spaced fracture surface facets . (b) PA-T8 (thick) microstructure in transverse direction at 209 MPa showing de...for later parts of this paper as de- lamination is a typical feature observed in aged Al-Li alloys [9]. In laminated structures, depending on the

  10. Improved Accident Tolerance of Austenitic Stainless Steel Cladding through Colossal Supersaturation with Interstitial Solutes

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Frank [Case Western Reserve Univ., Cleveland, OH (United States)

    2016-10-13

    We proposed a program-supporting research project in the area of fuel-cycle R&D, specifically on the topic of advanced fuels. Our goal was to investigate whether SECIS (surface engineering by concentrated interstitial solute – carbon, nitrogen) can improve the properties of austenitic stainless steels and related structural alloys such that they can be used for nuclear fuel cladding in LWRs (light-water reactors) and significantly excel currently used alloys with regard to performance, safety, service life, and accident tolerance.

  11. Cascaded-cladding-pumped cascaded Raman fiber amplifier.

    Science.gov (United States)

    Jiang, Huawei; Zhang, Lei; Feng, Yan

    2015-06-01

    The conversion efficiency of double-clad Raman fiber laser is limited by the cladding-to-core area ratio. To get high conversion efficiency, the inner-cladding-to-core area ratio has to be less than about 8, which limits the brightness enhancement. To overcome the problem, a cascaded-cladding-pumped cascaded Raman fiber laser with multiple-clad fiber as the Raman gain medium is proposed. A theoretical model of Raman fiber amplifier with multiple-clad fiber is developed, and numerical simulation proves that the proposed scheme can improve the conversion efficiency and brightness enhancement of cladding pumped Raman fiber laser.

  12. Metal-clad waveguide sensors

    DEFF Research Database (Denmark)

    Skivesen, Nina

    This work concerns planar optical waveguide sensors for biosensing applications, with the focus on deep-probe sensing for micron-scale biological objects like bacteria and whole cells. In the last two decades planar metal-clad waveguides have been brieflyintroduced in the literature applied...... for various biosensing applications, however a thorough study of the sensor configurations has not been presented, but is the main subject of this thesis. Optical sensors are generally well suited for bio-sensing asthey show high sensitivity and give an immediate response for minute changes in the refractive...... index of a sample, due to the high sensitivity of optical bio-sensors detection of non-labeled biological objects can be performed. The majority of opticalsensors presented in the literature and commercially available optical sensors are based on evanescent wave sensing, however most of these sensors...

  13. TEC – Thin Environmental Cladding

    Directory of Open Access Journals (Sweden)

    Alan Tomasi

    2015-05-01

    Full Text Available Permasteelisa Group developed with Fiberline Composites a new curtain wall system (Thin Environmental Cladding or TEC, making use of pultruded GFRP (Glass Fiber Reinforced Polymer material instead of traditional aluminum. Main advantages using GFRP instead of aluminum are the increased thermal performance and the limited environmental impact. Selling point of the selected GFRP resin is the light transmission, which results in pultruded profiles that allow the visible light to pass through them, creating great aesthetical effects. However, GFRP components present also weaknesses, such as high acoustic transmittance (due to the reduced weight and anisotropy of the material, low stiffness if compared with aluminum (resulting in higher facade deflection and sensible fire behavior (as combustible material. This paper will describe the design of the TEC-facade, highlighting the functional role of glass within the facade concept with regards to its acoustic, structural, aesthetics and fire behavior.

  14. CALCULATION OF STRESS AND DEFORMATION IN FUEL ROD CLADDING DURING PELLET-CLADDING INTERACTION

    Directory of Open Access Journals (Sweden)

    Dávid Halabuk

    2015-12-01

    Full Text Available The elementary parts of every fuel assembly, and thus of the reactor core, are fuel rods. The main function of cladding is hermetic separation of nuclear fuel from coolant. The fuel rod works in very specific and difficult conditions, so there are high requirements on its reliability and safety. During irradiation of fuel rods, a state may occur when fuel pellet and cladding interact. This state is followed by changes of stress and deformations in the fuel cladding. The article is focused on stress and deformation analysis of fuel cladding, where two fuels are compared: a fresh one and a spent one, which is in contact with cladding. The calculations are done for 4 different shapes of fuel pellets. It is possible to evaluate which shape of fuel pellet is the most appropriate in consideration of stress and deformation forming in fuel cladding, axial dilatation of fuel, and radial temperature distribution in the fuel rod, based on the obtained results.

  15. Texture Dependent Young's Modulus in Austenitic Cladding

    OpenAIRE

    1988-01-01

    In Austenitic claddings of pressure vessel steel columnar grains with a 〈100〉-fiber axis oriented perpendicular to the surface have been previously observed. The fiber axis is parallel to the steepest temperature gradient. Since high temperature gradients also exist in the plane of cladding, preferred orientation should be found there.This was proved with {111}- and {220}-pole figures taken of the cladding in addition to {200}-pole figures. From these pole figures it could be concluded that t...

  16. Cladding and Structural Materials for Advanced Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Was, G S; Allen, T R; Ila, D; C,; Levi,; Morgan, D; Motta, A; Wang, L; Wirth, B

    2011-06-30

    The goal of this consortium is to address key materials issues in the most promising advanced reactor concepts that have yet to be resolved or that are beyond the existing experience base of dose or burnup. The research program consists of three major thrusts: 1) high-dose radiation stability of advanced fast reactor fuel cladding alloys, 2) irradiation creep at high temperature, and 3) innovative cladding concepts embodying functionally-graded barrier materials. This NERI-Consortium final report represents the collective efforts of a large number of individuals over a period of three and a half years and included 9 PIs, 4 scientists, 3 post-docs and 12 students from the seven participating institutions and 8 partners from 5 national laboratories and 3 industrial institutions (see table). University participants met semi-annually and participants and partners met annually for meetings lasting 2-3 days and designed to disseminate and discuss results, update partners, address outstanding issues and maintain focus and direction toward achieving the objectives of the program. The participants felt that this was a highly successful program to address broader issues that can only be done by the assembly of a range of talent and capabilities at a more substantial funding level than the traditional NERI or NEUP grant. As evidence of the success, this group, collectively, has published 20 articles in archival journals and made 57 presentations at international conferences on the results of this consortium.

  17. Coupling between counterpropagating cladding modes in fiber Bragg gratings.

    Science.gov (United States)

    Sáez-Rodriguez, D; Cruz, J L; Díez, A; Andrés, M V

    2011-04-15

    We present an experimental demonstration of energy transfer between counterpropagating cladding modes in a fiber Bragg grating (FBG). A strong FBG written in a standard photosensitive optical fiber is illuminated with a single cladding mode, and the power transferred between the forward propagating cladding mode and different backward propagating cladding modes is measured by using two auxiliary long period gratings. Resonances between cladding modes having 30 pm bandwidth and 8 dB rejection have been observed.

  18. High Temperature and Pressure Steam-H2 Interaction with Candidate Advanced LWR Fuel Claddings

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A [ORNL

    2012-08-01

    This report summarizes the work completed to evaluate cladding materials that could serve as improvements to Zircaloy in terms of accident tolerance. This testing involved oxidation resistance to steam or H{sub 2}-50% steam environments at 800-1350 C at 1-20 bar for short times. A selection of conventional alloys, SiC-based ceramics and model alloys were used to explore a wide range of materials options and provide guidance for future materials development work. Typically, the SiC-based ceramic materials, alumina-forming alloys and Fe-Cr alloys with {ge}25% Cr showed the best potential for oxidation resistance at {ge}1200 C. At 1350 C, FeCrAl alloys and SiC remained oxidation resistant in steam. Conventional austenitic steels do not have sufficient oxidation resistance with only {approx}18Cr-10Ni. Higher alloyed type 310 stainless steel is protective but Ni is not a desirable alloy addition for this application and high Cr contents raise concern about {alpha}{prime} formation. Higher pressures (up to 20.7 bar) and H{sub 2} additions appeared to have a limited effect on the oxidation behavior of the most oxidation resistant alloys but higher pressures accelerated the maximum metal loss for less oxidation resistant steels and less metal loss was observed in a H{sub 2}-50%H{sub 2}O environment at 10.3 bar. As some of the results regarding low-alloyed FeCrAl and Fe-Cr alloys were unexpected, further work is needed to fundamentally understand the minimum Cr and Al alloy contents needed for protective behavior in these environments in order to assist in alloy selection and guide alloy development.

  19. Localization of plastic deformation in ultra-fine grained Al and Al-Li at temperatures of 4.2-350 K

    Science.gov (United States)

    Isaev, N. V.; Zabrodin, P. A.; Rusakova, A. V.

    2012-10-01

    This is a study of the plasticity of coarse-grained and ultrafine-grained Al and Al-Li obtained by severe plastic deformation. The temperature dependences of the uniform deformation ɛu(T) before it is localized as necking are examined in the light of the evolution of the density of dislocations and the effect of grain boundaries. The reduction in ɛu with rising temperature is caused by an increase in the rate of annihilation of screw dislocations, which is determined by the Seeger transverse shear stress. The sharp drop in ɛu for ultrafine-grained materials compared to coarse-grained materials is explained by an increase in their yield stress and a lower rate of work hardening owing to the enhanced role of grain boundaries as obstacles, sources, and sinks for dislocations. In this case, the deformation and microhardness distributions along the sample become highly nonuniform, and, as a measure of plasticity, ɛu no longer characterizes the high local plasticity of these materials.

  20. The study of the modes of Ta-Zr powder mixture non-vacuum electron-beam cladding on the surface of the cp-titanium plates

    Science.gov (United States)

    Samoylenko, V. V.; Lozhkina, E. A.; Polyakov, I. A.; Lenivtseva, O. G.; Ivanchik, I. S.; Matts, O. E.

    2016-11-01

    The effect of the modes of non-vacuum electron-beam cladding of Ta-Zr powder mixtures on the structure and properties of the layers formed on the surface of cp-titanium were studied. The mode of the electron-beam alloying of titanium with zirconium and tantalum, which ensured the formation of a defect-free layer with a high content of alloying elements was selected. Metallographic examination indicated the presence of a dendritic- and plate-type structure of cladded layers. The microhardness of the layers, formed at the optimum mode, was not changed in the cross section and was equal to 450 HV.

  1. Additive Manufacturing of High-Entropy Alloys by Laser Processing

    NARCIS (Netherlands)

    Ocelik, V.; Janssen, Niels; Smith, Stefan; De Hosson, J. Th M.

    2016-01-01

    This contribution concentrates on the possibilities of additive manufacturing of high-entropy clad layers by laser processing. In particular, the effects of the laser surface processing parameters on the microstructure and hardness of high-entropy alloys (HEAs) were examined. AlCoCrFeNi alloys with

  2. Reduction of Liquid Clad Formation Due to Solid State Diffusion in Clad Brazing Sheet

    Science.gov (United States)

    Benoit, Michael J.; Whitney, Mark A.; Wells, Mary A.; Winkler, Sooky

    2016-12-01

    Warm forming operations have shown promise in expanding automotive heat exchanger designs by increasing forming limits of clad brazing sheet. The impact of isothermal holds below the clad melting temperature on subsequent brazeability has not previously been studied in detail. The effect of these holds on brazeability, as measured by the clad thickness loss due to solid state diffusion of Si out of the clad layer prior to clad melting, was assessed through parallel DSC and optical microscopy measurements, as well as through the use of a previously developed model. EPMA measurements were also performed to support the other measures. Overall, the same trends were predicted by DSC, microscopy, and the theoretical model; however, the DSC predictions were unable to accurately predict remaining clad thickness prior to melting, even after correcting the data for clad-core interactions. Microscopy measurements showed very good agreement with the model predictions, although there were slight discrepancies at short hold times due to the inability of the model to account for clad loss during heating to the brazing temperature. Further microscopy measurements showed that when the heating rate is set below a critical value, there is a reduction in the clad thickness from the as-received condition.

  3. Advanced metal alloy systems for massive high-current photocathodes

    Science.gov (United States)

    Tkachenko, V. G.; Kondrashev, A. I.; Maksimchuk, I. N.

    2010-03-01

    The physical principles of precise alloying are formulated with the aim of increasing the low quantum efficiency (QE) of suitable simple metals (Mg, Al, Cu) as well as of decreasing their electron work function ( e φ) in the UV spectral range. The new approach provides valuable information for elucidating the origin of photoemission enhancement in bulk metal-based alloy systems. Bulk in-situ nanoclustering promises to be the most effective way of producing a much higher QE and a lower e φ in simple metals. In this article we show that the quantum efficiency of the metal-based alloys Mg-Ba, Al-Li, and Cu-BaO is considerably higher than the simple metals Mg, Al, and Cu, respectively. The spectral characteristics of the Mg-Ba, Al-Li and Cu-BaO systems obey the well-known Fowler square law for a near-free-electron model. The advanced metal alloys systems are promising photocathode materials usable for generation of high brightness electron beams.

  4. Birefringence analysis of segmented cladding fiber.

    Science.gov (United States)

    Kumar, Ajeet; Rastogi, Vipul; Agrawal, Arti; Rahman, B M A

    2012-05-20

    We present a full-vectorial modal analysis of a segmented cladding fiber (SCF). The analysis is based on the H-field vectorial finite element method (VFEM) employing polar mesh geometry. Using this method, we have analyzed the circular SCF and the elliptical SCF. We have found that the birefringence of the circular SCF is very small (1.0×10(-8)). Birefringence of a highly elliptical SCF can be altered to some extent by the number of segments and duty cycle of segmentation in the segmented cladding. However, the change is not profound. The analysis shows that the circular SCF possesses low birefringence and that the segmented cladding does not add any significant birefringence in an elliptical fiber. This result strongly indicates that small deviations in the segmented cladding parameters arising from fabrication process do not significantly affect the birefringence of the fiber.

  5. Plasmonic waveguides cladded by hyperbolic metamaterials

    DEFF Research Database (Denmark)

    Ishii, Satoshi; Shalaginov, Mikhail Y.; Babicheva, Viktoriia E.;

    2014-01-01

    Strongly anisotropic media with hyperbolic dispersion can be used for claddings of plasmonic waveguides (PWs). In order to analyze the fundamental properties of such waveguides, we analytically study 1D waveguides arranged from a hyperbolic metamaterial (HMM) in a HMM-Insulator-HMM (HIH) structure....... We show that HMM claddings give flexibility in designing the properties of HIH waveguides. Our comparative study on 1D PWs reveals that HIH-type waveguides can have a higher performance than MIM or IMI waveguides....

  6. Optimization of metal-clad waveguide sensors

    DEFF Research Database (Denmark)

    Skivesen, N.; Horvath, R.; Pedersen, H.C.

    2005-01-01

    The present paper deals with the optimization of metal-clad waveguides for sensor applications to achieve high sensitivity for adlayer and refractive index measurements. By using the Fresnel reflection coefficients both the angular shift and the width of the resonances in the sensorgrams are taken...... into account. Our optimization shows that it is possible for metal-clad waveguides to achieve a sensitivity improvement of 600% compared to surface-plasmon-resonance sensors....

  7. Obtention of fracture properties of unirradiated fuel cladding from ring compression tests

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Rengel, M.A. [Departamento de Ciencia de Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos Profesor Aranguren s/n, E-28040 Madrid (Spain); Consejo de Seguridad Nuclear (CSN), Justo Dorado 11, E-28040 Madrid (Spain); Gomez, F.J.; Ruiz-Hervias, J.; Caballero, L.; Valiente, A. [Departamento de Ciencia de Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos Profesor Aranguren s/n, E-28040 Madrid (Spain)

    2009-06-15

    Zirconium alloy cladding is used as the first structural barrier to contain the nuclear fuel and the fission products. In addition to its neutron transparency, this material has a good corrosion resistance and remarkable mechanical properties at operational temperatures. Consequently, it is or paramount importance to precisely characterize the mechanical behaviour and fracture properties of irradiated cladding to ensure a safe operation. It is known that the mechanical behaviour of unirradiated zirconium alloy cladding is anisotropic. The elastoplastic response depends on the direction, namely radial, hoop or longitudinal. For this reason, different fracture properties should be expected in each direction. From the various tests employed to characterize the mechanical behaviour along the hoop direction in nuclear fuel cladding, the ring compression test is particularly useful to study material fracture. With this test it is possible to determine the moment when a real crack is formed, due to a sudden decrease in the applied load at a given displacement value. The aim of this research is to determine as precisely as possible the value of the fracture energy from the ring compression test load vs. displacement curves. To this end, a finite element calculation incorporating the cohesive zone model was performed. In this case, the cohesive zone theory is applied in its simplest form. It is considered that the cohesive crack transfers a constant stress until the displacement of this cohesive crack reaches a critical value. At this precise moment a real crack is generated. The properties of the softening curve of the cohesive zone model can be obtained by directly comparing the experimental load vs. displacement records with the finite element calculations. The area under the softening curve is the fracture energy, which is directly related with the material fracture toughness. The experimental data used in this work have been obtained on unirradiated Zirlo cladding

  8. 3D analysis of thermal and stress evolution during laser cladding of bioactive glass coatings.

    Science.gov (United States)

    Krzyzanowski, Michal; Bajda, Szymon; Liu, Yijun; Triantaphyllou, Andrew; Mark Rainforth, W; Glendenning, Malcolm

    2016-06-01

    Thermal and strain-stress transient fields during laser cladding of bioactive glass coatings on the Ti6Al4V alloy basement were numerically calculated and analysed. Conditions leading to micro-cracking susceptibility of the coating have been investigated using the finite element based modelling supported by experimental results of microscopic investigation of the sample coatings. Consecutive temperature and stress peaks are developed within the cladded material as a result of the laser beam moving along the complex trajectory, which can lead to micro-cracking. The preheated to 500°C base plate allowed for decrease of the laser power and lowering of the cooling speed between the consecutive temperature peaks contributing in such way to achievement of lower cracking susceptibility. The cooling rate during cladding of the second and the third layer was lower than during cladding of the first one, in such way, contributing towards improvement of cracking resistance of the subsequent layers due to progressive accumulation of heat over the process.

  9. Surface protection of light metals by one-step laser cladding with oxide ceramics

    Science.gov (United States)

    Nowotny, S.; Richter, A.; Tangermann, K.

    1999-06-01

    Today, intricate problems of surface treatment can be solved through precision cladding using advanced laser technology. Metallic and carbide coatings have been produced with high-power lasers for years, and current investigations show that laser cladding is also a promising technique for the production of dense and precisely localized ceramic layers. In the present work, powders based on Al2O3 and ZrO2 were used to clad aluminum and titanium light alloys. The compact layers are up to 1 mm thick and show a nonporous cast structure as well as a homogeneous network of vertical cracks. The high adhesive strength is due to several chemical and mechanical bonding mechanisms and can exceed that of plasmasprayed coatings. Compared to thermal spray techniques, the material deposition is strictly focused onto small functional areas of the workpiece. Thus, being a precision technique, laser cladding is not recommended for large-area coatings. Examples of applications are turbine components and filigree parts of pump casings.

  10. Investigation of Hot Rolling Influence on the Explosive-Welded Clad Plate

    Directory of Open Access Journals (Sweden)

    Guanghui ZHAO

    2016-11-01

    Full Text Available The microstructure, the shear strength and tensile strength of stainless steel explosive-welded clad plate at different rolling reduction were studied. The mechanical properties of the explosive-welded and explosive-rolled clad plates were experimentally measured. Simultaneously, the microstructures of the clad plate were investigated by the Ultra deep microscope and the tensile fracture surface were observed by the scan electron microscope (SEM. It was observed that the tensile strength has been increased considerably, whereas the elongation percentage has been reduced with the increase of hot rolling reduction. In the tensile shear test, the bond strength is higher than the strength of the ferritic stainless steel layer and meets the relevant known standard criterion. Microstructural evaluations showed that the grain of the stainless steel and steel refined with the increase of thickness reduction. Examination of the tensile fracture surfaces reveal that, after hot rolling, the fracture in the low alloy steel and ferritic stainless steel clad plates is of the ductile type.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12409

  11. Fabrication of Tungsten-Rhenium Cladding materials via Spark Plasma Sintering for Ultra High Temperature Reactor Applications

    Energy Technology Data Exchange (ETDEWEB)

    Charit, Indrajit; Butt, Darryl; Frary, Megan; Carroll, Mark

    2012-11-05

    This research will develop an optimized, cost-effective method for producing high-purity tungsten-rhenium alloyed fuel clad forms that are crucial for the development of a very high-temperature nuclear reactor. The study will provide critical insight into the fundamental behavior (processing-microstructure- property correlations) of W-Re alloys made using this new fabrication process comprising high-energy ball milling (HEBM) and spark plasma sintering (SPS). A broader goal is to re-establish the U.S. lead in the research field of refractory alloys, such as W-Re systems, with potential applications in very high-temperature nuclear reactors. An essential long-term goal for nuclear power is to develop the capability of operating nuclear reactors at temperatures in excess of 1,000K. This capability has applications in space exploration and some special terrestrial uses where high temperatures are needed in certain chemical or reforming processes. Refractory alloys have been identified as being capable of withstanding temperatures in excess of 1,000K and are considered critical for the development of ultra hightemperature reactors. Tungsten alloys are known to possess extraordinary properties, such as excellent high-temperature capability, including the ability to resist leakage of fissile materials when used as a fuel clad. However, there are difficulties with the development of refractory alloys: 1) lack of basic experimental data on thermodynamics and mechanical and physical properties, and 2) challenges associated with processing these alloys.

  12. Fabrication and Lasing Property of Yb~(3+)-doped Double-Clad Fibers with Novel Inner Cladding

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The Yb3+-doped double-clad fibers with novel inner cladding have been made by using MCVD process, solution-doping method and optical machining together. The laser power and slope efficiency of the fiber lasers are higher than 1.8W and 50% respectively.

  13. Characterization of Gradient Ni-Fe/SiC Composite Coating on Mild Steel by Thermal Spraying in Combination with Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    Hu Mulin; Pan Lin; Fu Yongqing; Xie Changsheng; Wang Aihua

    2005-01-01

    Metal matrix composite coating Ni-Fe/SiC was prepared on an iron-based substrate by thermal spraying combined with laser cladding, using SiC particulates as the reinforcing agent. The microstructures of the coatings formed at different thermal spraying and laser cladding conditions were characterized by means of X-ray diffraction and electron probe microanalysis. The thermal oxidation properties of the mixed powders composed of different content of SiC particulates and relevant Ni-based alloy as the balance were examined using differential scanning calorimetry. The hardness profile of the thermal sprayed and laser cladding coatings was investigated as well. It was found that SiO2 particulates were generated and dissolved and dispersed during the melting and solidification of the laser cladding process, which was ascribed to the oxidation of the dispersed SiC particulates. The micro-hardness depth profile of the target laser cladding composite coating was characterized by gradient distribution, which could be related to the gradient distribution of the hard SiC and SiO2 particulates in the dendrites and interdendrites of the cladding layer. Both SiC and SiO2 particulates contributed to greatly increasing the microhardness and mechanical properties of the titled laser cladding composite coatings.

  14. TEC – Thin Environmental Cladding

    Directory of Open Access Journals (Sweden)

    Alan Tomasi

    2014-06-01

    Full Text Available Corresponding author: Alan Tomasi, Group R&D Project Manager, Permasteelisa S.p.A., viale E. Mattei 21/23 | 31029 Vittorio Veneto, Treviso, Italy. Tel.: +39 0438 505207; E-mail: a.tomasi@permasteelisagroup.com; www.permasteelisagroup.com Permasteelisa Group developed with Fiberline Composites a new curtain wall system (Thin Environmental Cladding or TEC, making use of pultruded GFRP (Glass Fiber Reinforced Polymer material instead of traditional aluminum. Main advantages using GFRP instead of aluminum are the increased thermal performance and the limited environmental impact. Selling point of the selected GFRP resin is the light transmission, which results in pultruded profiles that allow the visible light to pass through them, creating great aesthetical effects. However, GFRP components present also weaknesses, such as high acoustic transmittance (due to the reduced weight and anisotropy of the material, low stiffness if compared with aluminum (resulting in higher facade deflection and sensible fire behavior (as combustible material. This paper will describe the design of the TEC-facade, highlighting the functional role of glass within the facade concept with regards to its acoustic, structural, aesthetics and fire behavior.

  15. Measurement of Nucleate Pool Boiling Heat Transfer Limit using Fuel Cladding Material

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chi Young; Shin, Chang Hwan; Oh, Dong Seok; Chun, Tae Hyun; In, Wang Kee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Zircaloy has been widely used as a fuel cladding material of light water reactor for more than three decades because it has a lower neutron absorption cross section and cracking rate. Recently, HANA-6 has been developed in KAERI (Korea Atomic Energy Research Institute) as the advanced fuel cladding for high burn-up fuel. Generally, under the normal and accident operating conditions of a nuclear reactor, the nuclear fuel cladding of zirconium based alloys undergoes the surface change, and the oxide layer can be formed. In such a case, the previous CHF correlations should be assessed and examined using the experimental results for not a fresh zircaloy surface but an oxidized one, to predict and examine the thermal margin and safety of a nuclear reactor core. Therefore, the experimental data using the oxidized zircaloy surface need to be provided quantitatively. In this paper, the CHF in saturated water pool boiling is measured and discussed using the specimens of zircaloy-4, HANA-6, and oxidized zircaloy-4 in high temperature air environment. The CHF of zircaloy-4, HANA-6, and oxidized surface was tested. Zircaloy-4 and HANA-6 had a similar CHF performance. This is because both are the zirconium based alloys, and appear the almost same water contact angle. On the other hands, the oxidized specimen became to be higher CHF than plain zircaloy-4 and HANA-6 specimens, due to smaller water contact angle (i. e., good hydrophilicity of specimen). The Kandlikar's (2001) correlation reasonably predicted the present experimental data.

  16. Characterisation of a natural quartz crystal as a reference material for microanalytical determination of Ti, Al, Li, Fe, Mn, Ga and Ge

    Science.gov (United States)

    Audetat, Andreas; Garbe-Schonberg, Dieter; Kronz, Andreas; Pettke, Thomas; Rusk, Brian G.; Donovan, John J.; Lowers, Heather

    2015-01-01

    A natural smoky quartz crystal from Shandong province, China, was characterised by laser ablation ICP-MS, electron probe microanalysis (EPMA) and solution ICP-MS to determine the concentration of twenty-four trace and ultra trace elements. Our main focus was on Ti quantification because of the increased use of this element for titanium-in-quartz (TitaniQ) thermobarometry. Pieces of a uniform growth zone of 9 mm thickness within the quartz crystal were analysed in four different LA-ICP-MS laboratories, three EPMA laboratories and one solution-ICP-MS laboratory. The results reveal reproducible concentrations of Ti (57 ± 4 μg g-1), Al (154 ± 15 μg g-1), Li (30 ± 2 μg g-1), Fe (2.2 ± 0.3 μg g-1), Mn (0.34 ± 0.04 μg g-1), Ge (1.7 ± 0.2 μg g-1) and Ga (0.020 ± 0.002 μg g-1) and detectable, but less reproducible, concentrations of Be, B, Na, Cu, Zr, Sn and Pb. Concentrations of K, Ca, Sr, Mo, Ag, Sb, Ba and Au were below the limits of detection of all three techniques. The uncertainties on the average concentration determinations by multiple techniques and laboratories for Ti, Al, Li, Fe, Mn, Ga and Ge are low; hence, this quartz can serve as a reference material or a secondary reference material for microanalytical applications involving the quantification of trace elements in quartz.

  17. Intermetallic alloy welding wires and method for fabricating the same

    Science.gov (United States)

    Santella, M.L.; Sikka, V.K.

    1996-06-11

    Welding wires for welding together intermetallic alloys of nickel aluminides, nickel-iron aluminides, iron aluminides, or titanium aluminides, and preferably including additional alloying constituents are fabricated as two-component, clad structures in which one component contains the primary alloying constituent(s) except for aluminum and the other component contains the aluminum constituent. This two-component approach for fabricating the welding wire overcomes the difficulties associated with mechanically forming welding wires from intermetallic alloys which possess high strength and limited ductilities at elevated temperatures normally employed in conventional metal working processes. The composition of the clad welding wires is readily tailored so that the welding wire composition when melted will form an alloy defined by the weld deposit which substantially corresponds to the composition of the intermetallic alloy being joined. 4 figs.

  18. Analyses of cladding modes in photonic crystal fiber.

    Science.gov (United States)

    Park, Hyun Chul; Hwang, In Kag; Yeom, Dong Il; Kim, Byoung Yoon

    2007-11-12

    Characteristics of cladding modes in a photonic crystal fiber (PCF) are numerically analyzed using the plane wave expansion method. The presence of the outer silica ring in the PCF tends to push the optical fields of the cladding modes toward the rim of the PCF, which creates 'ring modes' whose fields are tightly confined in the outer ring. The dispersion of the cladding modes are determined mainly by the dispersive property of the holey cladding structure. The optical field patterns of the cladding modes and the beatlengths between the fundamental mode and the cladding modes are also investigated.

  19. The Effects of Retrogression and Reaging on Aluminum Alloy 2195

    Science.gov (United States)

    Ward, N.; Tran, A.; Abad, A.; Lee, E. W.; Hahn, M.; Fordan, E.; Es-Said, O.

    2011-08-01

    A retrogression and reaging (RRA) treatment was performed on 2195 Al-Li Alloy. The exposure times were from 5 to 60 min, and the temperatures were from 200 to 250 °C. Samples that were exposed to a salt spray test had overall similar mechanical properties as compared to those that were not exposed. The percent elongation, however, was significantly deteriorated due to the salt spray exposure. The mechanical properties of the 2195 samples were compared to those of 2099 samples exposed to similar treatments in an earlier study.

  20. 含B量对激光熔覆FeCoCrNiBx(x=0.5,0.75,1.0,1.25)高熵合金涂层组织结构与耐磨性的影响%Effect of Boron Addition on the Microstructure and Wear Resistance of FeCoCrNiBx (x=0.5, 0.75, 1.0, 1.25) High-Entropy alloy Coating Prepared by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    陈国进; 张冲; 唐群华; 戴品强

    2015-01-01

    采用激光熔覆技术制备FeCoCrNiBx高熵合金涂层,用X射线衍射(XRD)、扫描电镜(SEM)、硬度和耐磨测试等方法,研究了B含量对激光熔覆FeCoCrNiBx高熵合金涂层的组织结构、硬度和耐磨性能的影响.结果表明,随B含量的增加,合金相结构逐渐由fcc固溶体结构转变为fcc固溶体和M3B相共存,M3B相主要为Cr、Fe硼化物.随B含量的增加,枝晶组织中析出颗粒状和短棒状的M3B相,且M3B相逐渐长大成长条状.B的增加显著提高合金涂层的硬度,由4470 MPa增加到8480 MPa,且磨损量随着B的增加而减少.%The FeCoCrNiBx high-entropy alloy coatings were prepared by laser cladding.The effect of boron addition on microstructure,hardness and wear resistance of FeCoCrNiBx high-entropy alloy coating were investigated by X-ray diffraction (XRD),scanning electron microscopy (SEM),hardness and wear testers.The results show that with the boron addition increasing,the structure of alloys change from fcc structure to fcc structure with M3B phase precipitation,and M3B phase are mainly borides of Cr and Fe.Meanwhile,the granular and short rod-like M3B phase is precipitated in the coatings.And a blocky M3B phase forms with boron addition.Microhardness and wear resistance are significantly enhanced by the formation M3B phase.The microhardness increases from 4470 to 8480 MPa,and the wear-loss of FeCoCrNiBx high-entropy alloy coating decrease with boron addition.

  1. Investigation of Ni-Cr-Si-Fe-B coatings produced by the electron beam cladding technique

    Science.gov (United States)

    Zimogliadova, T. A.; Drobyaz, E. A.; Golkovskii, M. G.; Bataev, V. A.; Durakov, V. G.; Cherkasova, N. Yu

    2016-11-01

    This paper presents the results of structural investigations and results of tribological and microhardness tests of the coating obtained by electron beam cladding of a Ni-Cr-Si-Fe-B self-fluxing alloy on low-carbon steel. After electron beam treatment high-quality dense layer with a thickness of 1.2-1.8 mm was obtained. The structure of the coating consisted of dendrite crystals based on y-Ni-solid solution and eutectic with complex composition. Microhardness of the coating achieves 370 HV. Wear-resistance of the coating obtained by electron-beam cladding technique was 1.6-fold higher than that of low-carbon carburized steel.

  2. In-situ TiC Reinforced Composite Coating Produced by Powder Feeding Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    Sen YANG; Wenjin LIU; Minlin ZHONG

    2006-01-01

    A Ni-base alloy composite coating reinforced with TiC particles of various shapes and sizes on medium carbon steel substrate was produced by multilayer laser cladding. The chemical compositions, microstructures and surface morphology of the cladded layer were analyzed using energy dispersive X-ray spectroscopy (EDX),scanning electron microscope (SEM), and X-ray diffractometry (XRD). The experimental results showed that an excellent metallurgical bonding between the coating and the substrate was obtained. The microstructure of the coating was mainly composed of γ-Ni dendrites, a small amount of CrB, Ni3B, M23C6 and dispersed TiC particles. Much more and larger TiC particles formed in the overlapping zone, which led to a slightly higher microhardness of this zone. The maximum microhardness of the coating was about HV0.21200. The effects of the laser processing parameters on the microstructures and properties of coating were also investigated.

  3. Structure and Properties of Ti-Nb-C Coatings Obtained by Non-vacuum Electron Beam Cladding

    Science.gov (United States)

    Lenivtseva, O. G.; Polyakov, I. A.; Lazurenko, D. V.; Lozhkin, V. S.

    2015-10-01

    In this study the structure and properties of surface-alloyed cp-titanium layers obtained by non-vacuum electron beam cladding of niobium carbide powders were analyzed. A thickness of coatings fabricated by single-layer cladding was 1.3 mm. Cladding of the second layer led to an increase in the thickness by 0.8 mm. It was found that titanium carbide particles of different morphology acted as strengthening structural elements. The X-ray diffraction (XRD) analysis revealed the presence of α-Ti (α'-Ti), β-Ti, and TiC in the cladded layer. The results of the energy dispersive X-ray (EDX) analysis indicated the presence of Nb in the titanium matrix as well as in the carbide phase. However, such phases as NbC and (Nb, Ti)C were not identified by the XRD analysis. Transmission electron microscopy (TEM) revealed zones containing an increased amount of Nb. The structure of these zones was represented by the β-Ti and ω-Ti precipitation. An average microhardness value of cladded layers was approximately 330 HV.

  4. Thermal Shock Properties of Cladding with SiC{sub f}/SiC Composite Protective Films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Donghee; Park, Kwangheon [Kyunghee University, Yongin (Korea, Republic of); Kim, Weonju; Park, Jiyeon; Kim, Daejong; Lee, Hyeon Geun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    In general, Zr-4 alloy is used for such nuclear fuel cladding. Zr-4 possesses a very small thermal neutron absorption cross-section and has superior corrosion resistance in the normal operating conditions of a nuclear reactor. However, in the case of a critical accident such as a LOCA (loss-of-coolant accident) in the Fukushima disaster, the risk of hydrogen explosion becomes serious. That is, in the case of coolant leakage, a dramatic reaction between the nuclear fuel cladding and steam can cause a heating reaction accompanied by rapid high-temperature oxidation, while creating a huge amount of hydrogen. Hence, the search for an alternative material for nuclear fuel cladding is being actively undertaken. Ceramic-based nuclear fuel cladding is receiving much attention as a means of improving safety. SiC has excellent properties of resistance to high temperature and high exposure and superior mechanical properties, as well as a very small thermal neutron absorption cross-section (0.09 barns), which causes almost no decrease in mechanical strength or volume change following exposure. This experiment examined the thermal shock properties and microstructure of cladding that has SiCf/SiC composite protective film, using polycarbosilane preceramic polymer.

  5. Multilayer cladding with hyperbolic dispersion for plasmonic waveguides

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi;

    2015-01-01

    We study the properties of plasmonic waveguides with a dielectric core and multilayer metal-dielectric claddings that possess hyperbolic dispersion. The waveguides hyperbolic multilayer claddings show better performance in comparison to conventional plasmonic waveguides. © OSA 2015....

  6. The Absorption Characteristics of Inhomogeneous Double-Clad Fibers

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The absorption characteristics of radially inhomogeneous double-clad fiber (DCF) are investigated firstly with the method of caustic radius, combined with the method of WKBJ. The results are significant for double-clad optical fiber lasers and amplifiers.

  7. Capturing reflected cladding modes from a fiber Bragg grating with a double-clad fiber coupler.

    Science.gov (United States)

    Baiad, Mohamad Diaa; Gagné, Mathieu; Lemire-Renaud, Simon; De Montigny, Etienne; Madore, Wendy-Julie; Godbout, Nicolas; Boudoux, Caroline; Kashyap, Raman

    2013-03-25

    We present a novel measurement scheme using a double-clad fiber coupler (DCFC) and a fiber Bragg grating (FBG) to resolve cladding modes. Direct measurement of the optical spectra and power in the cladding modes is obtained through the use of a specially designed DCFC spliced to a highly reflective FBG written into slightly etched standard photosensitive single mode fiber to match the inner cladding diameter of the DCFC. The DCFC is made by tapering and fusing two double-clad fibers (DCF) together. The device is capable of capturing backward propagating low and high order cladding modes simply and efficiently. Also, we demonstrate the capability of such a device to measure the surrounding refractive index (SRI) with an extremely high sensitivity of 69.769 ± 0.035 μW/RIU and a resolution of 1.433 × 10(-5) ± 8 × 10(-9) RIU between 1.37 and 1.45 RIU. The device provides a large SRI operating range from 1.30 to 1.45 RIU with sufficient discrimination for all individual captured cladding modes. The proposed scheme can be adapted to many different types of bend, temperature, refractive index and other evanescent wave based sensors.

  8. Influence of powder particle injection velocity on the microstructure of Al-12Si/SiCp coatings produced by laser cladding

    NARCIS (Netherlands)

    Anandkumar, R.; Almeida, A.; Vilar, R.; Ocelik, V.; De Hosson, J. Th M.

    2009-01-01

    The influence of powder particle injection velocity on the microstructure of coatings consisting of an Al-Si matrix reinforced with SiC particles prepared by laser cladding from mixtures of powders of Al-12 wt.% Si alloy and SiC was investigated both experimentally and by modeling. At low injection

  9. Laser powder technology for cladding and welding

    Science.gov (United States)

    Arnold, J.; Volz, R.

    1999-06-01

    Laser powder technology offers several advantages compared to conventional cladding and welding techniques and is attracting increasing industrial interest. The laser materials processing group of the German Aerospace Center at Stuttgart, Germany, is currently developing these new methods for application in industrial process engineering. Key areas of the work include the design and implementation of a modular working head that can be universally used for laser welding and surface treatment, the development of powder nozzles for cladding and welding, and the construction of new systems for special applications (e.g., for inner cladding). Some of these developments are described, as well as some important examples that highlight the potential of welding and surface treatment using laser powder techniques.

  10. Mechanical modelling of transient- to- failure SFR fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Feria, F.; Herranz, L. E.

    2014-07-01

    The response of Sodium Fast Reactor (SFR) fuel rods to transient accident conditions is an important safety concern. During transients the cladding strain caused by the stress due to pellet cladding mechanical interaction (PCMI) can lead to failure. Due to the fact that SFR fuel rods are commonly clad with strengthened material made of stainless steel (SS), cladding is usually treated as an elastic-perfectly-plastic material. However, viscoplastic behaviour can contribute to mechanical strain at high temperature (> 1000 K). (Author)

  11. Phosphate-core silica-clad Er/Yb-doped optical fiber and cladding pumped laser.

    Science.gov (United States)

    Egorova, O N; Semjonov, S L; Velmiskin, V V; Yatsenko, Yu P; Sverchkov, S E; Galagan, B I; Denker, B I; Dianov, E M

    2014-04-07

    We present a composite optical fiber with a Er/Yb co-doped phosphate-glass core in a silica glass cladding as well as cladding pumped laser. The fabrication process, optical properties, and lasing parameters are described. The slope efficiency under 980 nm cladding pumping reached 39% with respect to the absorbed pump power and 28% with respect to the coupled pump power. Due to high doping level of the phosphate core optimal length was several times shorter than that of silica core fibers.

  12. Spatial Mode Selective Waveguide with Hyperbolic Cladding

    CERN Document Server

    Tang, Y; Xu, M; Bäumer, S; Adam, A J L; Urbach, H P

    2016-01-01

    Hyperbolic Meta-Materials~(HMMs) are anisotropic materials with permittivity tensor that has both positive and negative eigenvalues. Here we report that by using a type II HMM as cladding material, a waveguide which only supports higher order modes can be achieved, while the lower order modes become leaky and are absorbed in the HMM cladding. This counter intuitive property can lead to novel application in optical communication and photonic integrated circuit. The loss in our HMM-Insulator-HMM~(HIH) waveguide is smaller than that of similar guided mode in a Metal-Insulator-Metal~(MIM) waveguide.

  13. Finite-width plasmonic waveguides with hyperbolic multilayer cladding

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi;

    2015-01-01

    homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence...

  14. Analysis of failures of waterproofing cladding layers of terracotta tiles

    Directory of Open Access Journals (Sweden)

    Koláčný Milan

    2017-01-01

    Full Text Available The article is focused on one of the most important roof cladding layers – the waterproofing cladding layer of terracotta tiles. Its detailed analysis covers the main waterproofing cladding layers in terms of their material characteristics and installation methods. The article concludes by formulating principles for the correct design of the main waterproofing layer/construction.

  15. The use of slow strain rate technique for studying stress corrosion cracking of an advanced silver-bearing aluminum-lithium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Frefer, Abdulbaset Ali; Raddad, Bashir S. [Department of Mechanical and Industrial Engineering/Tripoli University, Tripoli (Libya); Abosdell, Alajale M. [Department of Mechanical Engineering/Mergeb University, Garaboli (Libya)

    2013-12-16

    In the present study, stress corrosion cracking (SCC) behavior of naturally aged advanced silver-bearing Al-Li alloy in NaCl solution was investigated using slow strain rate test (SSRT) method. The SSRT’s were conducted at different strain rates and applied potentials at room temperature. The results were discussed based on percent reductions in tensile elongation in a SCC-causing environment over those in air tended to express the SCC susceptbility of the alloy under study at T3. The SCC behavior of the alloy was also discussed based on the microstructural and fractographic examinations.

  16. The use of slow strain rate technique for studying stress corrosion cracking of an advanced silver-bearing aluminum-lithium alloy

    Science.gov (United States)

    Frefer, Abdulbaset Ali; Abosdell, Alajale M.; Raddad, Bashir S.

    2013-12-01

    In the present study, stress corrosion cracking (SCC) behavior of naturally aged advanced silver-bearing Al-Li alloy in NaCl solution was investigated using slow strain rate test (SSRT) method. The SSRT's were conducted at different strain rates and applied potentials at room temperature. The results were discussed based on percent reductions in tensile elongation in a SCC-causing environment over those in air tended to express the SCC susceptbility of the alloy under study at T3. The SCC behavior of the alloy was also discussed based on the microstructural and fractographic examinations.

  17. yb3+-Doped Double-Clad Fibre Laser Pumped by Rectangular Inner Cladding

    Institute of Scientific and Technical Information of China (English)

    宁鼎; 李乙刚; 黄榜才; 孙建军; 吕可诚; 袁树忠; 董孝义

    2001-01-01

    A novel Yb3+-doped double-clad silica fibre with rectangular inner cladding was designed and developed by using the modified chemical vapour deposition process, solution-doping and optical machining all together. The dimensions of the inner cladding are 100 × 70 μm, and Yb3+-doped concentration in the core is about 0.24 wt. %. The operation of the fibre laser pumped by inner cladding is reported. The threshold of the laser is 34mW.When the pump power launched is 141mW, the laser output is 84mW at the wavelength 1075.6nm, and the slope efficiency is 77%.

  18. Analysis of coaxial laser cladding processing conditions

    NARCIS (Netherlands)

    de Oliveira, U; Ocelik, V; De Hosson, JTM

    2005-01-01

    The formation of thick Ni-based coating on a steel substrate by coaxial laser cladding using the Nd:YAG 2 kW continuous laser was studied both from a theoretical and experimental point of view. The theoretical analysis concentrated on the transfer of laser irradiation and powder particles using a si

  19. Cladding For Transversely-Pumped Laser Rod

    Science.gov (United States)

    Byer, Robert L.; Fan, Tso Yee

    1989-01-01

    Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.

  20. CLAD CARBIDE NUCLEAR FUEL, THERMIONIC POWER, MODULES.

    Science.gov (United States)

    The general objective is to evaluate a clad carbide emitter, thermionic power module which simulates nuclear reactor installation, design, and...performance. The module is an assembly of two series-connected converters with a single common cesium reservoir. The program goal is 500 hours

  1. Development of weldable, corrosion-resistant iron-aluminide alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, P.J.; Goodwin, G.M.; Wang, X.L. [Oak Ridge National Laboratory, TN (United States)

    1995-05-01

    Corrosion-resistant, weldable FeAl alloys have been developed with improved high-temperature strength industrial applications. Previous processing difficulties with these alloys led to their evaluation as weld-overlay claddings on conventional structural steels to take advantage of their good properties now. Simplified and better processing methods for monolithic FeAl components are also currently being developed so that components for industrial testing can be made. Other avenues for producing FeAl coatings are currently being explored. Neutron scattering experiments residual stress distributions in the FeAl weld-overlay cladding began in FY 1993 and continued this year.

  2. Crack Free Tungsten Carbide Reinforced Ni(Cr) Layers obtained by Laser Cladding

    Science.gov (United States)

    Amado, J. M.; Tobar, M. J.; Yáñez, A.; Amigó, V.; Candel, J. J.

    The development of hardfacing coatings has become technologically significant in many industries A common approach is the production of metal matrix composites (MMC) layers. In this work NiCr-WC MMC hardfacing layers are deposited on C25 steel by means of laser cladding. Spheroidal fused tungsten carbides is used as reinforcement phase. Three different NiCr alloys with different Cr content were tested. Optimum conditions to obtain dense, uniform carbide distribution and hardness close to nominal values were defined. The effect of Cr content respect to the microstructure, susceptibility for cracking and the wear rate of the resulting coating will also be discussed.

  3. Interfacing VPSC with finite element codes. Demonstration of irradiation growth simulation in a cladding tube

    Energy Technology Data Exchange (ETDEWEB)

    Patra, Anirban [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tome, Carlos [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-23

    This Milestone report shows good progress in interfacing VPSC with the FE codes ABAQUS and MOOSE, to perform component-level simulations of irradiation-induced deformation in Zirconium alloys. In this preliminary application, we have performed an irradiation growth simulation in the quarter geometry of a cladding tube. We have benchmarked VPSC-ABAQUS and VPSC-MOOSE predictions with VPSC-SA predictions to verify the accuracy of the VPSCFE interface. Predictions from the FE simulations are in general agreement with VPSC-SA simulations and also with experimental trends.

  4. Corrosion of aluminum clad spent nuclear fuel in the 70 ton cask during transfer from L area to H-canyon

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-01

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33% was found after 1 year in the cask with a maximum temperature of 263 °C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 °C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  5. Corrosion of aluminum clad spent nuclear fuel in the 70 ton cask during transfer from L area to H-canyon

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-31

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33 % was found after 1 year in the cask with a maximum temperature of 263 °C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 °C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  6. CORROSION OF ALUMINUM CLAD SPENT NUCLEAR FUEL IN THE 70 TON CASK DURING TRANSFER FROM L AREA TO H-CANYON

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.

    2014-06-01

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33 % was found after 1 year in the cask with a maximum temperature of 260 {degrees}C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 {degrees}C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  7. Osteoblast interaction with laser cladded HA and SiO{sub 2}-HA coatings on Ti-6Al-4V

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yuling [Department of Physics, Northeastern University, Shenyang 110004 (China); Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Serpersu, Kaan [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); He Wei, E-mail: whe5@utk.edu [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Paital, Sameer R. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Dahotre, Narendra B. [Department of Materials Science and Engineering, University of North Texas, Denton, TX 76207 (United States)

    2011-12-01

    In order to improve the bioactivity and biocompatibility of titanium endosseous implants, the morphology and composition of the surfaces were modified. Polished Ti-6Al-4V substrates were coated by a laser cladding process with different precursors: 100 wt.% HA and 25 wt.% SiO{sub 2}-HA. X-ray diffraction of the laser processed samples showed the presence of CaTiO{sub 3}, Ca{sub 3}(PO{sub 4}){sub 2}, and Ca{sub 2}SiO{sub 4} phases within the coatings. From in vitro studies, it was observed that compared to the unmodified substrate all laser cladded samples presented improved cellular interactions and bioactivity. The samples processed with 25 wt.% SiO{sub 2}-HA precursor showed a significantly higher HA precipitation after immersion in simulated body fluid than 100 wt.% HA precursor and titanium substrates. The in vitro biocompatibility of the laser cladded coatings and titanium substrate was investigated by culturing of mouse MC3T3-E1 pre-osteoblast cell line and analyzing the cell viability, cell proliferation, and cell morphology. A significantly higher cell attachment and proliferation rate were observed for both laser cladded 100 wt.% HA and 25 wt.% SiO{sub 2}-HA samples. Compared to 100 wt.% HA sample, 25 wt.% SiO{sub 2}-HA samples presented a slightly improved cellular interaction due to the addition of SiO{sub 2}. The staining of the actin filaments showed that the laser cladded samples induced a normal cytoskeleton and well-developed focal adhesion contacts. Scanning electron microscopic image of the cell cultured samples revealed better cell attachment and spreading for 25 wt.% SiO{sub 2}-HA and 100 wt.% HA coatings than titanium substrate. These results suggest that the laser cladding process improves the bioactivity and biocompatibility of titanium. The observed biological improvements are mainly due to the coating induced changes in surface chemistry and surface morphology. Highlights: {yields} Laser cladding of Ti alloys with bioceramics creates new

  8. PFR fuel cladding transient test results and analysis

    Science.gov (United States)

    Cannon, N. S.; Hunter, C. W.; Kear, K. L.; Wood, M. H.

    1986-05-01

    Fuel Cladding Transient Tests (FCTT) were performed on M316 cladding specimens obtained from mixed-oxide fuel pins irradiated in the Prototype Fast Reactor (PFR) to burnups of 4 and 9 atom percent. In these tests, specimens of fuel cladding were pressurized and heated until failure occurred. Samples of cladding from PFR fuel pins exhibited generally greater strength and ductility than specimens from Experimental Breeder Reactor-II (EBR-II) mixed-oxide fuel pins tested under similar conditions. Apparently, the PFR cladding properties were not degraded by a fuel adjacency effect (FAE) observed in fuel pin cladding from EBR-II irradiations. A recently developed model of grain boundary cavity growth was used to predict the results of the tests conducted on PFR cladding. It was found that the predicted failure temperatures for the relevant internal pressures were in good agreement with experimental failure temperatures.

  9. Three-Ply Al/Mg/Al Clad Sheets Fabricated by Twin-Roll Casting and Post-treatments (Homogenization, Warm Rolling, and Annealing)

    Science.gov (United States)

    Park, Jaeyeong; Song, Hyejin; Kim, Jung-Su; Sohn, Seok Su; Lee, Sunghak

    2016-11-01

    When thin Al alloy sheets are clad on to twin-roll-cast Mg alloy melt, inherent drawbacks of Mg alloys such as poor formability, corrosion resistance, and surface quality can be effectively complemented. In this study, three-ply Al/Mg/Al clad sheets were fabricated by twin-roll casting and post-treatments. Brittle interfacial layers composed of γ (Mg17Al12) and β (Mg2Al3) phases were inevitably formed, but their proper thickening during the post-treatments led to improvement of interfacial bonding and resultant tensile properties. In particular, warm rolling was an effective way to modify interfacial microstructures and tensile properties by minimizing deformation inhomogeneity and stress concentration.

  10. Three-Ply Al/Mg/Al Clad Sheets Fabricated by Twin-Roll Casting and Post-treatments (Homogenization, Warm Rolling, and Annealing)

    Science.gov (United States)

    Park, Jaeyeong; Song, Hyejin; Kim, Jung-Su; Sohn, Seok Su; Lee, Sunghak

    2017-01-01

    When thin Al alloy sheets are clad on to twin-roll-cast Mg alloy melt, inherent drawbacks of Mg alloys such as poor formability, corrosion resistance, and surface quality can be effectively complemented. In this study, three-ply Al/Mg/Al clad sheets were fabricated by twin-roll casting and post-treatments. Brittle interfacial layers composed of γ (Mg17Al12) and β (Mg2Al3) phases were inevitably formed, but their proper thickening during the post-treatments led to improvement of interfacial bonding and resultant tensile properties. In particular, warm rolling was an effective way to modify interfacial microstructures and tensile properties by minimizing deformation inhomogeneity and stress concentration.

  11. Microstructure and Tribological Properties of In-situ Synthesized TiB2-TiC/Ni Based Composite Coating by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    SUNRong-lu; TANGYing; YANGXian-jin

    2004-01-01

    A TiB2 and TiC particles reinforced Ni based composites coating was prepared on TC4 alloy surface by chemical reaction among Ti, B and C elements using laser cladding technique. Microstructural analysis showed that the sizes of in-situ synthesized TiB2 and TiC particles ranged within 5-10μm and 1-2μm, respectively, while both the two kinds of particles were uniformly distributed in the clad layer. The measurement of microhardness and wear and friction propert iesindicated that the microhardness of laser clad layer was HV900-1100, being three times of that of the TC4 alloy; the friction coefficient of the laser clad layer in air and in vacuum (10-5Pa) ranged within 0.2-0.3 and 0.3-0.5, respectively; the wear rate in terms of mass loss was considerably lower than that of the TC4 alloy both in air and in vacuum environment.

  12. Microstructure and Tribological Properties of In-situ Synthesized TiB2- TiC/Ni Based Composite Coating by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    SUN Rong-lu; TANG Ying; YANG Xian-jin

    2004-01-01

    ATiB2 and TiC particles reinforced Ni based composites coating was prepared on TC4 alloy surface by chemical reaction among Ti, B and C elements using laser cladding technique. Microstructural analysis showed that the sizes of in-situ synthesized TiB2 and TiC particles ranged within 5~10μm and 1~2μn, respectively, while both the two kinds of particles were uniformly distributed in the clad layer. The measurement of microhardness and wear and friction properties indicated that the microhardness of laser clad layer was HV900~1100, being three times of that of the TC4 alloy; the friction coefficient of the laser clad layer in air and in vacuum (10-5 Pa) ranged within 0.2~0.3 and 0.3~0.5, respectively; the wear rate in terms of mass loss was considerably lower than that of the TC4 alloy both in air and in vacuum environment.

  13. Simulation on function mechanism of Tl(Al2CuLi) precipitate in localized corrosion of Al-Cu-Li alloys

    Institute of Scientific and Technical Information of China (English)

    LI Jin-feng; ZHENG Zi-qiao; REN Wen-da; CHEN Wen-jing; ZHAO Xu-shan; LI Shi-chen

    2006-01-01

    To clarify the corrosion mechanism associated with the precipitate of T1(Al2CuLi) in Al-Li alloys, the simulated bulk precipitate of T1 was fabricated through melting and casting. Its electrochemical behavior and coupling behavior with a(Al) in 3.5%NaCl solution were investigated. Meanwhile, the simulated Al alloy containing T1 particle was prepared and its corrosion morphology was observed. The results show that there exists a dynamic conversion corrosion mechanism associated with the precipitate of T1. At the beginning, the precipitate of T1 is anodic to the alloy base and corrosion occurs on its surface. However,during its corrosion process, its potential moves to a positive direction with immersion time increasing, due to the preferential dissolution of Li and the enrichment of Cu. As a result, the corroded T1 becomes cathodic to the alloy base at a later stage, leading to the anodic dissolution and corrosion of the alloy base at its adjacent periphery. It is suggested that the localized corrosion associated with the precipitate of T1 in Al-Li alloys is caused by the alternate anodic dissolution of the T1 precipitate and the alloy base at its adjacent periphery.

  14. New method to calculate the mechanical properties of unirradiated fuel cladding from ring tensile tests

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Rengel, M.A. [Departamento de Ciencia de Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos, Profesor Aranguren s/n, E-28040 Madrid (Spain); Consejo de Seguridad Nuclear (CSN), Justo Dorado 11, E-28040 Madrid (Spain); Gomez, F.J.; Ruiz-Hervias, J.; Caballero, L.; Valiente, A. [Departamento de Ciencia de Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos, Profesor Aranguren s/n, E-28040 Madrid (Spain)

    2009-06-15

    Nuclear fuel cladding is the first barrier used to confine the fuel and the fission products produced during irradiation. Zirconium alloys are used for this purpose due to their remarkable neutron transparency, together with their good mechanical properties at operational temperatures. Consequently, it is very important to be able to characterize the mechanical response of the irradiated cladding. The mechanical behaviour of the material can be modelled as elastoplastic with different stress-strain curves depending on the direction: radial, hoop or longitudinal direction. The ring tensile test has been proposed to determine the mechanical properties of the cladding along the hoop direction. The initial test consisted of applying a force inside the tube, by means of two half cylinders. Later Arsene and Bai [1,2] modified the experimental device to avoid tube bending at the beginning of the test. The same authors proposed a numerical method to obtain the stress-strain curve in the hoop direction from the experimental load versus displacement results and a given friction coefficient between the loading pieces and the sample [3]. This method has been used by different authors [4] with slight modifications. It is based on the existence of two universal curves under small strain hypothesis: the first correlating the hoop strain and the displacement of the loading piece and the second one correlating the hoop stress and the applied load. In this work, a new method to determine the mechanical properties of the cladding from the ring tensile test results is proposed. Non-linear geometry is considered and an iterative procedure is proposed so universal curves are not needed. A stress-strain curve is determined by combining numerical calculations with experimental results in a convergent loop. The two universal curves proposed by Arsene and Bai [3] are substituted by two relationships, one between the equivalent plastic strain in the centre of the specimen ligament and the

  15. Investigation of Microstructure in Solid State Welded Al-Cu-Li alloy

    Directory of Open Access Journals (Sweden)

    No Kookil

    2016-01-01

    Full Text Available Al-Li alloys have been extensively used in aerospace vehicle structure since the presence of lithium increases the modulus and reduce the density of the alloy. Especially the third generation Al-Cu-Li alloy shows enhanced fracture toughness at cryogenic temperatures so that the alloy has been used on the fuel tank of space launchers, like Super Lightweight External Tank of the Space Shuttle. Since the commercial size of the plate cannot accommodate the large tank size of the launcher, joining several pieces is required. However, lithium is highly reactive and its compounds can decompose with heat from conventional fusion welding and form different types of gases which result in formation of defects. In this study, the microstructure change is investigated after solid state welding process to join the Al-Cu-Li sheets with optical and transmission electron microscopic analysis of precipitates.

  16. Temperature and stress fields of multi-track laser cladding

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hong-yun; ZHANG nong-tao; XU Chun-hua; YANG Xian-qun

    2009-01-01

    Based on genetic algorithm and neural network algorithm, the finite element analyses on the temperature fields and stress fields of multi-track laser cladding were carried out by using the ANSYS software. The results show that, in the multi-track cladding process, the temperature field ellipse leans to the cladding formed, and the front cladding has preheating function on the following cladding. During cladding, the longitudinal stress is the largest, the lateral stress is the second, and the thickness direction stress is the smallest. The center of the cladding is in the tensile stress condition. The longitudinal tensile stress is higher than the lateral or thickness direction stress by several times, and the tensile stress achieves the maximum at the area of joint between the cladding and substrate. Therefore, it is inferred that transversal crack is the most main crack form in multi-track laser cladding. Moreover, the joint between cladding and substrate is the crack sensitive area, and this is consistent with the actual experiments.

  17. Suppression of transverse-mode spurious responses for SAW resonators on SiO2/Al/LiNbO3 structure by selective removal of SiO2.

    Science.gov (United States)

    Nakamura, Hiroyuki; Nakanishi, Hidekazu; Goto, Rei; Hashimoto, Ken-ya

    2011-10-01

    A SiO(2)/Al/LiNbO(3) structure has a large electromechanical coupling factor (K(2)) and good temperature coefficient of frequency (TCF) for applications as a SAW duplexer of the Universal Mobile Telecommunications System (UMTS) Band I. However, the SiO(2)/Al/LiNbO(3) structure also supports two unwanted spurious responses; one is caused by the Rayleigh mode and the other by the transverse mode. As the authors have previously discussed, the Rayleigh-mode spurious response can be suppressed by controlling the cross-sectional shape of a SiO(2) overlay deposited on resonator electrodes. In this paper, a new technique to suppress the transverse-mode spurious responses is proposed. In the technique, the SiO(2) overlay is selectively removed from the dummy electrode region. The spurious responses are analyzed by the laser probe system. The results indicate that the spurious responses in question were hybrid modes caused by the coupling between the main (SH) SAW and another (Rayleigh) SAW with different velocities. The hybrid-mode spurious behavior was dependent on the velocities in the IDT and the dummy regions (v(i) and v(d)). The hybrid-mode spurious responses could be suppressed by selectively removing SiO(2). Furthermore, the SAW energy confinement could be enhanced in the IDT electrode region when v(i) < v(d). The transverse-mode spurious responses were successfully suppressed without degrading the SAW resonator performances.

  18. Impacts of transient heat transfer modeling on prediction of advanced cladding fracture during LWR LBLOCA

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youho, E-mail: euo@kaist.ac.kr; Lee, Jeong Ik, E-mail: jeongiklee@kaist.ac.kr; NO, Hee Cheon, E-mail: hcno@kaist.ac.kr

    2016-03-15

    Highlights: • Use of constant heat transfer coefficient for fracture analysis is not sound. • On-time heat transfer coefficient should be used for thermal fracture prediction. • ∼90% of the actual fracture stresses were predicted with the on-time transient h. • Thermal-hydraulic codes can be used to better predict brittle cladding fracture. • Effects of surface oxides on thermal shock fracture should be accounted by h. - Abstract: This study presents the importance of coherency in modeling thermal-hydraulics and mechanical behavior of a solid for an advanced prediction of cladding thermal shock fracture. In water quenching, a solid experiences dynamic heat transfer rate evolutions with phase changes of the fluid over a short quenching period. Yet, such a dynamic change of heat transfer rates has been overlooked in the analysis of thermal shock fracture. In this study, we are presenting quantitative evidence against the prevailing use of a constant heat transfer coefficient for thermal shock fracture analysis in water. We conclude that no single constant heat transfer could suffice to depict the actual stress evolution subject to dynamic fluid phase changes. Use of the surface temperature dependent heat transfer coefficient will remarkably increase predictability of thermal shock fracture of brittle materials. The presented results show a remarkable stress prediction improvement up to 80–90% of the actual stress with the use of the surface temperature dependent heat transfer coefficient. For thermal shock fracture analysis of brittle fuel cladding such as oxidized zirconium-based alloy or silicon carbide during LWR reflood, transient subchannel heat transfer coefficients obtained from a thermal-hydraulics code should be used as input for stress analysis. Such efforts will lead to a fundamental improvement in thermal shock fracture predictability over the current experimental empiricism for cladding fracture analysis during reflood.

  19. Development and property evaluation of nuclear grade wrought FeCrAl fuel cladding for light water reactors

    Science.gov (United States)

    Yamamoto, Y.; Pint, B. A.; Terrani, K. A.; Field, K. G.; Yang, Y.; Snead, L. L.

    2015-12-01

    Development of nuclear grade, iron-based wrought FeCrAl alloys has been initiated for light water reactor (LWR) fuel cladding to serve as a substitute for zirconium-based alloys with enhanced accident tolerance. Ferritic alloys with sufficient chromium and aluminum additions can exhibit significantly improved oxidation kinetics in high-temperature steam environments when compared to zirconium-based alloys. In the first phase, a set of model FeCrAl alloys containing 10-20Cr, 3-5Al, and 0-0.12Y in weight percent, were prepared by conventional arc-melting and hot-working processes to explore the effect of composition on the properties of FeCrAlY alloys. It was found that the tensile properties were insensitive to the alloy compositions studied; however, the steam oxidation resistance strongly depended on both the chromium and the aluminum contents. The second phase development focused on strengthening Fe-13Cr-5Al with minor alloying additions of molybdenum, niobium, and silicon. Combined with an optimized thermo-mechanical treatment, a thermally stable microstructure was produced with improved tensile properties at temperatures up to 741 °C.

  20. Biocompatibility of a functionally graded bioceramic coating made by wide-band laser cladding.

    Science.gov (United States)

    Weidong, Zhu; Qibin, Liu; Min, Zheng; Xudong, Wang

    2008-11-01

    The application of plasma spray is the most popular method by which a metal-bioceramic surface composite can be prepared for the repair of biological hard-tissue, but this method has disadvantages. These disadvantages include poor coating-to-substrate adhesion, low mechanical strength, and brittleness of the coating. In the investigation described in this article, a gradient bioceramic coating was prepared on a Ti-6Al-4V titanium alloy surface using a gradient composite design and wide-band laser cladding techniques. Using a trilayer-structure composed of a substratum, an alloy and bioceramics, the coating was chemically and metallurgically bonded with the substratum. The coating, which contains beta-tricalcium phosphate and hydroxyapatite, showed favorable biocompatibility with the bone tissue and promoted in vivo osteogenesis.

  1. Cavitation-erosion mechanism of laser cladded SiC particle reinforced metal matrix composite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-hua; ZHANG Song; YANG Hong-gang; ZHU Sheng-long; MAN Hau-chung; CAI Qing-kui

    2005-01-01

    With 2 kW continuous wave Nd-YAG laser,SiC ceramic powder was laser-cladded on the AA6061 aluminium alloy surface.Within the range of process parameters investigated,the parameters were optimized to produce the SiCp reinforced metal matrix composites(MMC) modified layer on AA6061 alloy surface.After being treated,the modified layer is crack-free,porosity free,and has good metallurgical bond with the substrate.The microstructure and chemical composition of the modified layer were analyzed by such detection devices as scanning electronic microscope(SEM-EDX) and X-ray diffractometer(XRD).The performance of electrochemical corrosion and cavitation erosion and their mechanism were estimated by the microhardness tester,potentiostat and ultrasonicinduced cavitation device.

  2. Microstructure stability of candidate stainless steels for Gen-IV SCWR fuel cladding application

    Science.gov (United States)

    Li, Jian; Zheng, W.; Penttilä, S.; Liu, P.; Woo, O. T.; Guzonas, D.

    2014-11-01

    In the past few years, significant progress has been made in materials selection for Gen-IV SCWR fuel cladding applications. Current studies indicate that austenite stainless steels such as 310H are promising candidates for in-core applications. Alloys in this group are promising for their corrosion resistance, SCC resistance, high temperature mechanical properties and creep resistance at temperatures up to 700 °C. However, one under-studied area of this alloy is the long-term microstructure stability under the proposed reactor operating condition. Unstable microstructure not only results in embrittlement but also has the potential to reduce their resistance to corrosion or stress-corrosion cracking. In this study, stainless steels 310H and 304H were tested for their SCWR corrosion resistance and microstructure stability.

  3. Influence of laser cladding regimes on structural features and mechanical properties of coatings on titanium substrates

    Energy Technology Data Exchange (ETDEWEB)

    Malyutina, Yulia N., E-mail: iuliiamaliutina@gmail.ru; Lazurenko, Daria V., E-mail: pavlyukova-87@mail.ru; Bataev, Ivan A., E-mail: ivanbataev@ngs.ru [Novosibirsk State Technical University, Novosibirsk, 630073 (Russian Federation); Movtchan, Igor A., E-mail: igor.movtchan@enise.fr [National Engineering School in Saint-Etienne, Saint-Etienne, 42000 France (France)

    2015-10-27

    In this paper an influence of the tantalum content on the structure and properties of surface layers of the titanium alloy doped using a laser treatment technology was investigated. It was found that an increase of a quantity of filler powder per one millimeter of a track length contributed to a rise of the content of undissolved particles in coatings. The maximum thickness of a cladded layer was reached at the mass of powder per the length unit equaled to 5.5 g/cm. Coatings were characterized by the formation of a dendrite structure with attributes of segregation. The width of a quenched fusion zone grew with an increase in the rate of powder feed to the treated area. Significant strengthening of the titanium surface layer alloyed with tantalum was not observed; however, the presence of undissolved tantalum particles can decrease the hardness of titanium surface layers.

  4. Radiation Effects in Refractory Alloys

    Science.gov (United States)

    Zinkle, Steven J.; Wiffen, F. W.

    2004-02-01

    In order to achieve the required low reactor mass per unit electrical power for space reactors, refractory alloys are essential due to their high operating temperature capability that in turn enables high thermal conversion efficiencies. One of the key issues associated with refractory alloys is their performance in a neutron irradiation environment. The available radiation effects data are reviewed for alloys based on Mo, W, Re, Nb and Ta. The largest database is associated with Mo alloys, whereas Re, W and Ta alloys have the least available information. Particular attention is focused on Nb-1Zr, which is a proposed cladding and structural material for the reactor in the Jupiter Icy Moons Orbiter (JIMO) project. All of the refractory alloys exhibit qualitatively similar temperature-dependent behavior. At low temperatures up to ~0.3TM, where TM is the melting temperature, the dominant effect of radiation is to produce pronounced radiation hardening and concomitant loss of ductility. The radiation hardening also causes a dramatic decrease in the fracture toughness of the refractory alloys. These low temperature radiation effects occur at relatively low damage levels of ~0.1 displacement per atom, dpa (~2×1024 n/m2, E>0.1 MeV). As a consequence, operation at low temperatures in the presence of neutron irradiation must be avoided for all refractory alloys. At intermediate temperatures (0.3 to 0.6 TM), void swelling and irradiation creep are the dominant effects of irradiation. The amount of volumetric swelling associated with void formation in refractory alloys is generally within engineering design limits (>10 dpa). Very little experimental data exist on irradiation creep of refractory alloys, but data for other body centered cubic alloys suggest that the irradiation creep will produce negligible deformation for near-term space reactor applications.

  5. Impact of reactor water chemistry on cladding performance

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B. [University of Toronto, Centre for Nuclear Engineering, Toronto, Ontario (Canada)

    1997-07-01

    Water chemistry may have a major impact on fuel cladding performance in PWRs. If the saturation temperature on the surface of fuel cladding is exceeded, either because of the thermal hydraulics of the system, or because of crud deposition, then LiOH concentration can occur within thick porous oxide films on the cladding. This can degrade the protective film and accelerate the corrosion rate of the cladding. If sufficient boric acid is also present in the coolant then these effects may be mitigated. This is normally the case through most of any reactor fuel cycle. Extensive surface boiling may disrupt this equilibrium because of the volatility of boric acid in steam. Under such conditions severe cladding corrosion can ensue. The potential for such effects on high burnup cladding in CANDU reactors, where bone acid is not present in the primary coolant, is discussed. (author)

  6. Cladded single crystal fibers for high power fiber lasers

    Science.gov (United States)

    Kim, W.; Shaw, B.; Bayya, S.; Askins, C.; Peele, J.; Rhonehouse, D.; Meyers, J.; Thapa, R.; Gibson, D.; Sanghera, J.

    2016-09-01

    We report on the recent progress in the development of cladded single crystal fibers for high power single frequency lasers. Various rare earth doped single crystal YAG fibers with diameters down to 17 μm with length > 1 m have been successfully drawn using a state-of-the-art Laser Heated Pedestal Growth system. Single and double cladding on rare earth doped YAG fibers have been developed using glasses where optical and physical properties were precisely matched to doped YAG core single crystal fiber. The double clad Yb:YAG fiber structures have dimensions analogous to large mode area (LMA) silica fiber. We also report successful fabrications of all crystalline core/clad fibers where thermal and optical properties are superior over glass cladded YAG fibers. Various fabrication methods, optical characterization and gain measurements on these cladded YAG fibers are reported.

  7. Producing titanium-niobium alloy by high energy beam

    Energy Technology Data Exchange (ETDEWEB)

    Sharkeev, Yu. P., E-mail: sharkeev@ispms.tsc.ru [Institute of Strength Physics and Materials Science, SB RAS, 2/4 Akademicheski Prosp., Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Golkovski, M. G., E-mail: golkoski@mail.ru [Budker Institute of Nuclear Physics, 11 Akademika Lavrentiev Prosp., Novosibirsk, 630090 (Russian Federation); Glukhov, I. A., E-mail: gia@ispms.tsc.ru; Eroshenko, A. Yu., E-mail: eroshenko@ispms.tsc.ru; Fortuna, S. V., E-mail: s-fortuna@mail.ru [Institute of Strength Physics and Materials Science, SB RAS, 2/4 Akademicheski Prosp., Tomsk, 634055 (Russian Federation); Bataev, V. A., E-mail: bataev@vadm.ustu.ru [Novosibirsk State Technical University, 20 K. Marx Prosp., Novosibirsk, 630073 (Russian Federation)

    2016-01-15

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element.

  8. Thermodynamic Calculations of Melt in Melt Pool During Laser Cladding High Silicon Coatings

    Institute of Scientific and Technical Information of China (English)

    DONG Dan-yang; LIU Chang-sheng; ZHANG Bin

    2008-01-01

    Based on the Miedema's formation heat model for binary alloys and the Toop's asymmetric model for terna-ry alloys, the formation heat, excess entropy, and activity coefficients of silicon ranging from 1 900 K to 4 100 K in the Fe-Si-C melt formed during the laser cladding high silicon coatings process were calculated. The results indicated that all values of InγOSi, εCSi, ρSiSi and ρCSi are negative in the temperature range and these values increase as the tempera-ture increases. And all values of εSiSi and ρSi-CSi are positive and these values decrease with increasing temperature. The iso-activity lines of silicon are distributed axisymmetrically to the incident laser beam in the melt pool vertical to the laser scanning direction. And the iso-activity lines of silicon in the front of the melt pool along the laser scanning direction are more intensive than those in the back of the melt pool. The activity of silicon on the bottom of the melt pool is lower than that in the effecting center of laser beam on the top surface of the melt pool and it may be the im-portant reason for the formation of the silicides and excellent metallurgical bonding between the laser cladding coating and the substrate.

  9. The fatigue response of the aluminium-lithium alloy, 8090

    Science.gov (United States)

    Birt, M. J.; Beevers, C. J.

    1989-01-01

    The fatigue response of an Al-Li-Cu-Mg-Zr (8090) alloy has been studied at room temperature. The initiation and growth of small and long cracks has been examined at R = 0.1 and at a frequency of 100 Hz. Initiation was observed to occur dominantly at sub-grain boundaries. The growth of the small cracks was crystallographic in character and exhibited little evidence of retardation or arrest at the grain boundaries. The long crack data showed the alloy to have a high resistance to fatigue crack growth with underaging providing the optimum heat treatment for fatigue crack growth resistance. In general, this can be attributed to high levels of crack closure which resulted from the presence of extensive microstructurally related asperities.

  10. Clad fiber capacitor and method of making same

    Science.gov (United States)

    Tuncer, Enis

    2012-12-11

    A clad capacitor and method of manufacture includes assembling a preform comprising a ductile, electrically conductive fiber; a ductile, electrically insulating cladding positioned on the fiber; and a ductile, electrically conductive sleeve positioned over the cladding. One or more preforms are then bundled, heated and drawn along a longitudinal axis to decrease the diameter of the ductile components of the preform and fuse the preform into a unitized strand.

  11. Pellet-clad interaction in water reactor fuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The aim of this seminar is was to draw up a comprehensive picture of the pellet clad interaction and its impact on the fuel rod. This document is a detailed abstract of the papers presented during the following five sessions: industrial goals, fuel material behaviour in PCI situation, cladding behaviour relevant to PCI, in pile rod behaviour and modelling of the mechanical interaction between pellet and cladding. (A.L.B.)

  12. Water-moderated reactor fuel cladding reliability study

    OpenAIRE

    Бакутяк, Елена Викторовна; Пелых, Сергей Николаевич

    2014-01-01

    Considering the fuel element, averaged by fuel assembly (FA) of water-moderated reactor with the power of 1000 MW (VVER-1000), the number of fuel elements with the greatest cladding failure probability after 4 operation years at Khmelnitsky NPP-2 (KNPP-2) is found. This will allow to calculate the fuel cladding failure probability and determine the most likely cladding damages, which will enable to improve the performance and economic indexes of VVER.The novelty of the paper lies in calculati...

  13. The Study Programm Report of the Corrosion Behavior of New Zirconium-based Alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The corrosion of fuel cladding in PWR limits the extension of burnup. To compare the corrosion resistance of Zr-4 and new zirconium-based alloys, the out-of-pile water-side corrosion test has been conducted for these materials.To study the effects of heat flux on the corrosion of cladding, and keep the surface of cladding as an original ’as-received’ statement, the heat elements are introduced into the inside of the cladding tubes.The materials have been exposed for 205 d till now. The oxide film performed on the surface of cladding is black and glossy. The thickness of oxide is measured by the method of eddy current.

  14. Simulation Study of Al-1Mn/Al-10Si Circular Clad Ingots Prepared by Direct Chill Casting

    Science.gov (United States)

    Wu, Li; Kang, Huijun; Chen, Zongning; Fu, Ying; Wang, Tongmin

    2016-02-01

    A modified direct chill casting process based on Novelis FusionTM Technology co-casting process was used recently to prepare Al-1Mn/Al-10Si circular clad ingots. In the current study, a comprehensive simulation model was developed to investigate the direct chill casting process for preparing the Al-1Mn/Al-10Si circular clad ingots, and a parametric study and experimental research of the direct chill casting process was conducted to explore potential success and failure casting conditions. The simulation results revealed the bonding mechanism of the Al-1Mn/Al-10Si interface in the direct chill casting process and identified the effect of certain parameters on casting performance. The results indicated that the effect of casting speed and Al-1Mn casting temperature on the variations of the minimum solid fraction of Al-1Mn at the interface is stronger than that of cooling water flow rate in inner mold, while Al-10Si casting temperature is the weakest of the four casting parameters. The corresponding experimental results verified that Al-1Mn/Al-10Si circular clad ingot with acceptable metallurgical bonding can be successfully prepared by direct chill casting process under the proper casting parameters. The thickness of diffusion zone is about 40 μm, and the fractured position in tensile test was located in the Al-1Mn alloy side which indicated the strength of the interfacial region is higher than that of Al-1Mn alloy.

  15. Annular-cladding erbium doped multicore fiber for SDM amplification.

    Science.gov (United States)

    Jin, Cang; Ung, Bora; Messaddeq, Younès; LaRochelle, Sophie

    2015-11-16

    We propose and numerically investigate annular-cladding erbium doped multicore fibers (AC-EDMCF) with either solid or air hole inner cladding to enhance the pump power efficiency in optical amplifiers for spatial division multiplexing (SDM) transmission links. We first propose an all-glass fiber in which a central inner cladding region with a depressed refractive index is introduced to confine the pump inside a ring-shaped region overlapping the multiple signal cores. Through numerical simulations, we determine signal core and annular pump cladding parameters respecting fabrication constraints. We also propose and examine a multi-spot injection scheme for launching the pump in the annular cladding. With this all-glass fiber with annular cladding, our results predict 10 dB increase in gain and 21% pump power savings compared to the standard double cladding design. We also investigate a fiber with an air hole inner cladding to further enhance the pump power confinement and minimize power leaking into the inner cladding. The results are compared to the all-glass AC-EDMCF.

  16. Nuclear reactor fuel element with vanadium getter on cladding

    Science.gov (United States)

    Johnson, Carl E.; Carroll, Kenneth G.

    1977-01-01

    A nuclear reactor fuel element is described which has an outer cladding, a central core of fissionable or mixed fissionable and fertile fuel material and a layer of vanadium as an oxygen getter on the inner surface of the cladding. The vanadium reacts with oxygen released by the fissionable material during irradiation of the core to prevent the oxygen from reacting with and corroding the cladding. Also described is a method for coating the inner surface of small diameter tubes of cladding with a layer of vanadium.

  17. Second harmonic generation in thin optical fibers via cladding modes.

    Science.gov (United States)

    Elzahaby, Eman A; Kandas, Ishac; Aly, Moustafa H

    2016-05-30

    Since silica goes under the category of amorphous materials, it is difficult to investigate important processes such as second harmonic generation (SHG) in silica-based fibers. In this paper, we proposed a method for SHG relaying on cladding modes as pump modes. Cladding modes are introduced in optical fibers through tilted long period grating (T-LPG), where power of core mode is transferred into cladding modes. By functionalizing T-LPG with nonlinear coating, the interaction occurs between cladding modes and the coating material, consequently second harmonic signal (SHS) is generated with efficiency up to 0.14%.

  18. Finite-width plasmonic waveguides with hyperbolic multilayer cladding.

    Science.gov (United States)

    Babicheva, Viktoriia E; Shalaginov, Mikhail Y; Ishii, Satoshi; Boltasseva, Alexandra; Kildishev, Alexander V

    2015-04-20

    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence, are strongly absorbed. By avoiding the resonant widths in the design of the actual waveguides, the strong absorption can be eliminated.

  19. Hollow core anti-resonant fibres with split cladding

    Science.gov (United States)

    Huang, Xiaosheng; Qi, Wenliang; Ho, Daryl; Luan, Feng; Yong, Ken-Tye; Yoo, Seongwoo

    2016-03-01

    A split cladding fibers (SCF) is proposed as an additional design to the anti-resonant type fiber. The introduced split cladding helps to reduce the fabrication distortion. We use numerical simulations to compare the Kagome fibers (KFs) and the proposed split cladding fibers (SCFs) over two normalized transmission bands. It reveals that SCFs are able to maintain the desired round shape of silica cladding walls, hence improving the confinement loss (CL) compared to the KF. Fabrication of the SCF is demonstrated by the stack-and-draw technique. The near filed mode patterns are measured to prove the feasibility of this fiber design.

  20. Microstructural Characterization of Cermet Cladding Developed Through Microwave Irradiation

    Science.gov (United States)

    Gupta, Dheeraj; Sharma, Apurbba Kumar

    2012-10-01

    In the present work, cladding of hardfacing WC10Co2Ni powder on austenitic stainless steel has been developed through a novel processing technique. The clads were developed using microwave hybrid heating. The clad of average thickness ~2 mm has been developed through the exposure of microwave radiation at frequency 2.45 GHz and power 900 W for the duration of 360 s. The developed clads were characterized using field emission scanning electron microscope, X-ray elemental analysis, X-ray diffraction, and measurement of Vicker's microhardness. The microstructure study of the clad showed good metallurgical bonding with substrate and revealed that clads are free from any visible interface cracking. Clads were formed with partial dilution of a thin layer of the substrate. The cermet microstructure mainly consists of relatively soft metallic matrix phase and uniformly distributed hard carbide phase with skeleton-like structure. The developed clads exhibit an average microhardness of 1064 ± 99 Hv. The porosity of developed clad has been significantly less at approximately 0.89%.

  1. Clad strip casting by a twin roll caster

    OpenAIRE

    T. Haga; Nakamura, R; S. Kumai; H. Watari

    2009-01-01

    Purpose: Of this paper is to realize the casting of the clad strip by only one process. Therefore, the investigation of the ability of the casting of the clad strip by a vertical type twin roll caster was operated. The aim of the use of the twin roll caster to make clad strip was in the reduction of the production-energy of the clad strip.Design/methodology/approach: Used in the present study was a vertical type twin roll caster with the scriber. The scriber was used to prevent the mixture of...

  2. Design and fabrication of triangular inner cladding double-clad ytterbium doped fibre for high power lasers

    Institute of Scientific and Technical Information of China (English)

    Fu Yong-Jun; Jian Wei; Zheng Kai; Yan Feng-Ping; Chang De-Yuan; Jian Shui-Sheng

    2005-01-01

    To improve the performance of double clad high power fibre lasers, inner cladding design plays a significant role.A triangular inner cladding and silica structure second cladding with large air holes to acquire high inner cladding numerical aperture are designed. Single mode and high power output of the fibre lasers need the double clad Yb doped fibre with large core. A fibre with annular refractive index distribution core and low numerical aperture to acquire a large mode area fibre core is designed and fabricated. Furthermore co-doping with aluminium (Al) has been used to improve the solubility of ytterbium (Yb) into silicate network, and the core absorption coefficients of two Yb doped fibres are compared with different Al concentration experimentally.

  3. Suppression of Cladding Mode Coupling by B/Ge Codoped Photosensitive Fiber With Photosensitive and Depressed Inner Cladding

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Excess loss on the short wavelength side of the Bragg resonant wavelength caused by cladding mode coupling limits wide use of grating in the fiber communication system, especially in densed wavelength division multiplexing (DWDM) system.A novel photosensitive fiber design that have depressed cladding and photosensitive inner cladding in the same fiber is proposed, which can suppress cladding mode coupling greatly.Using MCVD method B/Ge codoped fiber with depressed cladding was fabriceted out, which was also doped in boron and germanium and had the photosensitivity.Finally, the transmission spectrum of written grating in this fiber by phase mask method verified its larger photosensitivity and greatly suppression of cladding mode coupling.

  4. Simulating the corrosion of zirconium alloys in the water coolant of VVER reactors

    Science.gov (United States)

    Kritskii, V. G.; Berezina, I. G.; Motkova, E. A.

    2013-07-01

    A model for predicting the corrosion of cladding zirconium alloys depending on their composition and operating conditions is proposed. Laws of thermodynamics and chemical kinetics of the reactions through which the multicomponent zirconium alloy is oxidized in the reactor coolant constitute the physicochemical heart of the model. The developed version of the model is verified against the results obtained from tests of fuel rod claddings made of commercial-grade and experimental zirconium alloys carried out by different researchers under autoclave and reactor conditions. It is shown that the proposed model adequately describes the corrosion of alloys in coolants used at nuclear power stations. It is determined that, owing to boiling of coolant and its acidification in a VVER-1200 reactor, Zr-1% Nb alloys with additions of iron and oxygen must be more resistant to corrosion than the commercial-grade alloy E110.

  5. Thermomechanical loading applied on the cladding tube during the pellet cladding mechanical interaction phase of a rapid reactivity initiated accident

    OpenAIRE

    2014-01-01

    International audience; Calculations of the CABRI REP-Na5 pulse were performed with the ALCYONE code in order to determine the evolution of the thermomechanical loading applied on the cladding tube during the Pellet-Cladding Mechanical Interaction (PCMI) phase of a rapid Reactivity Initiated Accident (RIA) initiated at 280 °C that lasted 8.8 ms. The evolution of the following parameters are reported: the cladding temperature, heating rate, strain rate and loading biaxiality. The impact of the...

  6. Influence of the pulsed plasma treatment on the corrosion resistance of the low-alloy steel plated by Ni-based alloy

    Science.gov (United States)

    Dzhumaev, P.; Yakushin, V.; Kalin, B.; Polsky, V.; Yurlova, M.

    2016-04-01

    This paper presents investigation results of the influence of high temperature pulsed plasma flows (HTPPF) treatment on the corrosion resistance of low-alloy steel 0.2C-Cr-Mn- Ni-Mo cladded by the rapidly quenched nickel-based alloy. A technique that allows obtaining a defect-free clad layer with a good adhesion to the substrate was developed. It is shown that the preliminary treatment of steel samples by nitrogen plasma flows significantly increases their corrosion resistance in the conditions of intergranular corrosion test in a water solution of sulfuric acid. A change of the corrosion mechanism of the clad layer from intergranular to uniform corrosion was observed as a result of sub-microcrystalline structure formation and homogeneous distribution of alloying elements in the plasma treated surface layer thus leading to the significant increase of the corrosion resistance.

  7. Effect of B4 C content on wear resistance of argon arc clad layer with in situ reactive alloy powder%B4C含量对原位反应型合金粉末氩弧熔覆层耐磨性的影响

    Institute of Scientific and Technical Information of China (English)

    马壮; 谭士海

    2014-01-01

    Argon arc cladding test was carried out on Q 235 steel with reduced iron powder , boron carbide powder and borax .Effects of boron carbide content (6%, 8%, 10%and 12%, mass fraction) on microstructure and wear resistance of the clad layers were investigated .The results show that when the boron carbide content is 12%, there is new phase Fe 2 B existing in the clad layer .With the increase of boron carbide content , the hardness , abrasive wear , adhesive wear and erosion wear resistance of the clad layer are gradually improved , when the boron carbide content reaches 12%, the hardness is 3.2 times of the matrix, and the relative abrasive wear , adhesive wear and erosion wear resistances are 5.4, 3.7 and 4.3 times of the matrix, respectively.%采用还原铁粉、碳化硼粉末、硼砂在基体金属材料Q235钢板上进行氩弧熔覆,并研究了6%、8%、10%、12%(质量分数)四种不同碳化硼含量对熔覆层组织和耐磨性的影响。结果表明,当碳化硼含量达到12%时熔覆层有新形成的Fe2 B,随碳化硼含量的增加熔覆层硬度、抗磨粒磨损性能、抗黏着磨损性能、抗冲蚀磨损性能逐渐提高,当碳化硼含量达到12%时,硬度是基体的3.2倍,相对耐磨粒磨损、黏着磨损、冲蚀磨损性能都大幅度提高,分别是基体的5.4、3.7、4.3倍。

  8. Design of Matched Cladding Fiber with UV-sensitive Cladding for Minimization of Claddingmode Losses in Fiber Bragg Gratings

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup; Berendt, Martin Ole; Bjarklev, Anders Overgaard;

    2000-01-01

    The effect on the Bragg-grating-induced cladding-mode coupling of varying the extent of the photosensitive region in a step-index fiber is analyzed. We introduce a figure of merit for the suppression of cladding-mode loss and compare different matched cladding fiber designs. It is found...... to be advantageous to increase the extent of the photosensitive region. However, no significant improvement is obtained by extending the photosensitive region more than approximately 10 mu m into the cladding. This result is not in agreement with a simple analysis that neglects UV absorption, which suggests...

  9. Thermomechanical loading applied on the cladding tube during the pellet cladding mechanical interaction phase of a rapid reactivity initiated accident

    Science.gov (United States)

    Hellouin de Menibus, Arthur; Sercombe, Jerome; Auzoux, Quentin; Poussard, Christophe

    2014-10-01

    Calculations of the CABRI REP-Na5 pulse were performed with the ALCYONE code in order to determine the evolution of the thermomechanical loading applied on the cladding tube during the Pellet-Cladding Mechanical Interaction (PCMI) phase of a rapid Reactivity Initiated Accident (RIA) initiated at 280 °C that lasted 8.8 ms. The evolution of the following parameters are reported: the cladding temperature, heating rate, strain rate and loading biaxiality. The impact of these parameters on the cladding mechanical behavior and fracture are then briefly reviewed.

  10. Microstructure, Wear, and Corrosion Characteristics of TiC-Laser Surface Cladding on Low-Carbon Steel

    Science.gov (United States)

    El-Labban, Hashem F.; Mahmoud, Essam Rabea Ibrahim; Algahtani, Ali

    2016-04-01

    Laser cladding was used to produce surface composite layer reinforced with TiC particles on low-carbon steel alloy for improving the wear and corrosion resistances. The cladding process was carried out at powers of 2800, 2000, 1500, and 1000 W, and a fixed traveling speed of 4 mm/s. The produced layers are free from any cracks. Some of the TiC particles were melted and then re-solidified in the form of fine acicular dendrites. The amount of the melted TiC was increased by increasing the laser power. The hardness of the produced layers was improved by about 19 times of the base metal. Decreasing laser power led to hardness increment at the free surface. The improvement in wear resistance was reached to about 25 times (in case of 1500 W) of the base metal. Moreover, the corrosion resistance shows remarkable improvement after the laser treatment.

  11. Microstructure and Corrosion Resistance of Cr7C3/γ-Fe Ceramal Composite Coating Fabricated by Plasma Cladding

    Institute of Scientific and Technical Information of China (English)

    LIU Junbo

    2007-01-01

    A new type in situ Cr7C3/γ-Fe ceramal composite coating was fabricated on substrate of hardened and tempered grade C steel by plasma cladding with Fe-Cr-C alloy powders. The ceramal composite coating has a rapidly solidified microstructure consisting of primary Cr7C3 and the Cr7C3/γ-Fe eutectics, and is metallurgically bonded to the degree C steel substrate. The corrosion resistances of the coating in water solutions of 0.5 mol/L H2SO4 and 3.5% NaCl were evaluated utilizing the electrochemical polarization corrosion-test method. Because of the inherent excellent corrosion-resisting properties of the constituting phase and the rapidly solidified homogeneous microstructure, the plasma clad ceramal composite coating exhibits excellent corrosion resistance in the water solutions of 0.5 mol/L H2SO4 and 3.5% NaCl.

  12. Metallographic Analyses of Laser Cladded WC-Ni and WC-Co Hard-facing Metals

    Institute of Scientific and Technical Information of China (English)

    HK Chikwanda; M Chiremba; C Van Rooyen

    2004-01-01

    Laser cladding is performed to improve the surface properties of metallic machine components. Extensive work is being conducted to investigate the relationships among the cladding parameters, clad powder characteristics and the quality of the clad layer. This work presents some of the metallographic analyses results of WC -Ni and WC-Co clad layers. The clad layers are characterised with non-uniform carbide particles, mostly WC imbedded in a more ductile matrix.The transition from the clad layer to the substrate metal had a distinct dilution zone. The ratio of this zone to the clad height was in the range of 10 -12% and this still needs to be refined.

  13. Improving the tribocorrosion resistance of Ti6Al4V surface by laser surface cladding with TiNiZrO2 composite coating

    Science.gov (United States)

    Obadele, Babatunde Abiodun; Andrews, Anthony; Mathew, Mathew T.; Olubambi, Peter Apata; Pityana, Sisa

    2015-08-01

    Ti6Al4V alloy was laser cladded with titanium, nickel and zirconia powders in different ratio using a 2 kW CW ytterbium laser system (YLS). The microstructures of the cladded layers were examined using field emission scanning electron microscopy (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD). Corrosion and tribocorrosion tests were performed on the cladded surface in 1 M H2SO4 solution. The microstructure revealed the transformation from a dense dendritic structure in TiNi coating to a flower-like structure observed in TiNiZrO2 cladded layers. There was a significant increase in surface microindentation hardness values of the cladded layers due to the present of hard phase ZrO2 particles. The results obtained show that addition of ZrO2 improves the corrosion resistance property of TiNi coating but decrease the tribocorrosion resistance property. The surface hardening effect induced by ZrO2 addition, combination of high hardness of Ti2Ni phase could be responsible for the mechanical degradation and chemical wear under sliding conditions.

  14. Scratch Behaviors of Cr-Coated Zr-Based Fuel Claddings for Accident-Tolerant Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Ho; Kim, Il-Hyun; Kim, Hyun-Gil; Kim, Hyung-Kyu; Koo, Yang-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    As the progression of Fukushima accident is worsened by the runaway reaction at a high temperature above 1200 .deg. C, it is essential to ensure the stabilities of coating layers on conventional Zr-based alloys during normal operations as well as severe accident conditions. This is because the failures of coating layer result in galvanic corrosion phenomenon by potential difference between coating layer and Zr alloy. Also, it is possible to damage the coating layer during handling and manufacturing process by contacting structural components of a fuel assembly. So, adhesion strength is one of the key factors determining the reliability of the coating layer on conventional Zr-based alloy. In this study, two kinds of Cr-coated Zr-based claddings were prepared using arc ion plating (AIP) and direct laser (DL) coating methods. The objective is to evaluate the scratch deformation behaviors of each coating layers on Zr alloys. Large area spallation below normal load of about 15 N appeared to be the predominant mode of failure in the AIP coating during scratch test. However, no tensile crack were found in entire stroke length. In DL coating, small plastic deformation and grooving behavior are more dominant scratching results. It was observed that the change of the slope of the COF curve did not coincide with the failure of coating layer.

  15. Photonic lantern with cladding-removable fibers

    Science.gov (United States)

    Sun, Weimin; Yan, Qi; Bi, Yao; Yu, Haijiao; Liu, Xiaoqi; Xue, Jiuling; Tian, He; Liu, Yongjun

    2014-07-01

    Recently, spectral measurement becomes an important tool in astronomy to find exoplanets etc. The fibers are used to transfer light from the focal plate to spectrometers. To get high-resolution spectrum, the input slits of the spectrometers should be as narrow as possible. In opposite, the light spots from the fibers are circle, which diameters are clearly wider than the width of the spectrometer slits. To reduce the energy loss of the fiber-guide star light, many kinds of image slicers were designed and fabricated to transform light spot from circle to linear. Some different setup of fiber slicers are introduced by different research groups around the world. The photonic lanterns are candidates of fiber slicers. Photonic lantern includes three parts: inserted fibers, preform or tubing, taped part of the preform or tubing. Usually the optical fields concentrate in the former-core area, so the light spots are not uniform from the tapered end of the lantern. We designed, fabricated and tested a special kind of photonic lantern. The special fibers consist polymer cladding and doped high-index core. The polymer cladding could be easily removed using acetone bath, while the fiber core remains in good condition. We inserted the pure high-index cores into a pure silica tubing and tapered it. During the tapering process, the gaps between the inserted fibers disappeared. Finally we can get a uniform tapered multimode fiber end. The simulation results show that the longer the taper is, the lower the loss is. The shape of the taper should be controlled carefully. A large-zone moving-flame taper machine was fabricated to make the special photonic lantern. Three samples of photonic lanterns were fabricated and tested. The lanterns with cladding-removable fibers guide light uniform in the tapered ends that means these lanterns could collect more light from those ends.

  16. Evolución de la fricción interna del material compuesto de matriz Al-Li 8090 reforzado con partículas de SiC

    Directory of Open Access Journals (Sweden)

    Gutiérrez-Urrutia, I.

    2001-04-01

    Full Text Available The present study has been undertaken to investigate the mechanism of thermal stress relief at the range of temperatures below room temperature for the metal matrix composite Al-Li 8090/SiC. For this aim the experimental technique of internal friction has been used which has been showed up very effective. Several thermal cycles from 453 K to 100 K were used in order to measure the internal friction as well as the elastic modulus of the material concluding that thermal stresses are relaxed by microplastic deformation around the reinforcements. It has been also related the variation in the elastic modulus with the different levels of precipitation.

    El presente trabajo investiga el mecanismo de relajación de tensiones térmicas a temperaturas por debajo de la de ambiente en el material compuesto Al-Li 8090/SiC. Para ello se ha empleado la técnica experimental de fricción interna que se ha mostrado la más eficaz para tal fin. Aplicando diferentes ciclos térmicos de 453 K a 100 K se midió tanto la fricción interna como el módulo elástico del material concluyendo que el mecanismo de relajación de tensiones térmicas es el de microdeformación plástica alrededor del reforzamiento. También se relaciona la variación del módulo elástico con los diferentes estadios de precipitación.

  17. Role of the micro/macro structure of welds in crack nucleation and propagation in aerospace aluminum-lithium alloy

    Science.gov (United States)

    Talia, George E.

    1996-01-01

    Al-Li alloys offer the benefits of increased strength, elastic modulus and lower densities as compared to conventional aluminum alloys. Martin Marietta Laboratories has developed an Al-Li alloy designated 2195 which is designated for use in the cryogenic tanks of the space shuttle. The Variable Polarity Plasma Arc (VPPA) welding process is currently being used to produce these welds [1]. VPPA welding utilizes high temperature ionized gas (plasma) to transfer heat to the workpiece. An inert gas, such as Helium, is used to shield the active welding zone to prevent contamination of the molten base metal with surrounding reactive atmospheric gases. [1] In the Space Shuttle application, two passes of the arc are used to complete a butt-type weld. The pressure of the plasma stream is increased during the first pass to force the arc entirely through the material, a practice commonly referred to as keyholing. Molten metal forms on either side of the arc and surface tension draws this liquid together as the arc passes. 2319 Al alloy filler material may also be fed into the weld zone during this pass. During the second pass, the plasma stream pressure is reduced such that only partial penetration of the base material is obtained. Al 2319 filler material is added during this pass to yield a uniform, fully filled welded joint. This additional pass also acts to alter the grain structure of the weld zone to yield a higher strength joint.

  18. Characterization of Nanoprecipitation Mechanisms During Isochronal Aging of a Pseudo-binary Al-8.7 at. pct Li Alloy

    Science.gov (United States)

    Spowage, A. C.; Bray, S.

    2011-01-01

    The addition of lithium to aluminium alloys is known to afford the dual advantages of increasing mechanical performance while lowering density. These characteristics make Al-Li alloys particularly desirable for aerospace applications. However, the complex precipitation pathways and extensive nanometer-sized decomposition products, termed "nanoprecipitates," make characterization difficult and thus limits optimization of the property sets of commercial alloys. This investigation uses thermal analysis and electrical resistivity methods to further understanding of the evolution of the various nanoprecipitates during isochronal aging of an Al-8.7 at. pct Li alloy. The results indicate decomposition via the following pathway: Spinodal-Ordering → Congruent Ordering + Spinodal Decomposition + Dissolution of Small Spinodally ordered regions → Growth of δ' → Dissolution of δ' → Nucleation and Growth followed by Dissolution of the δ phase.

  19. GEH-4-63, 64: Proposal for irradiation of production brazed Zircaloy-2 clad fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Tverberg, J.C.

    1961-05-18

    A brazed end closure is currently being used on prototypical NPR fuel elements. The production closure will use a braze alloy composed of 5% Be + 95% Zry-2 to braze the Zircaloy-2 cap to the jacket and to the metallic uranium core. A similar MTR test, a GEH-4-57, 58, used a braze alloy of the composition 4% Be + 12% Fe + 84% Zry-2 which melts at a lower temperature. In this previous test, element GEH-4-57 failed through a cladding defect located at the base of the braze heat affected zone. Because of this failure it would be desirable to subject a fuel element, which had been subjected to more severe brazing conditions, to the same conditions as GEH-4-57, 58. For this reason the thermal conditions of this test essentially match those of GEH-4-57, 58. This irradiation test consists of two identical fuel elements. The fuel material is normal metallic uranium, Zircaloy-2 clad of the tubular geometry, NPR inner size. The fuel was coextruded at Hanford by General Electric`s Fuels Preparation Department. Each element is 10.8 inches in length with flat Zircaloy-2 end caps brazed to the jacket and uranium core with the 5 Be + 95 Zry-2 brazing alloy, then TIG welded to further insure closure integrity. The elements ar 1.254 inches OD and 0.439 inches ID. For hydraulic purposes a 0.343 inch diamater flow restrictor has been fitted into the central flow channel of both elements.

  20. Compact cladding-pumped planar waveguide amplifier and fabrication method

    Science.gov (United States)

    Bayramian, Andy J.; Beach, Raymond J.; Honea, Eric; Murray, James E.; Payne, Stephen A.

    2003-10-28

    A low-cost, high performance cladding-pumped planar waveguide amplifier and fabrication method, for deployment in metro and access networks. The waveguide amplifier has a compact monolithic slab architecture preferably formed by first sandwich bonding an erbium-doped core glass slab between two cladding glass slabs to form a multi-layer planar construction, and then slicing the construction into multiple unit constructions. Using lithographic techniques, a silver stripe is deposited and formed at a top or bottom surface of each unit construction and over a cross section of the bonds. By heating the unit construction in an oven and applying an electric field, the silver stripe is then ion diffused to increase the refractive indices of the core and cladding regions, with the diffusion region of the core forming a single mode waveguide, and the silver diffusion cladding region forming a second larger waveguide amenable to cladding pumping with broad area diodes.